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Nudging. A tool for sustainable behaviour?


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This study was conducted as part of a government commission which was given to the Swedish Environmental Protection Agency (Swedish EPA) in 2014. The Environmental Protection Agency mandated the International Institute for Industrial Environmental Economics (IIIEE) at Lund University to conduct a research study on nudging. The study has served and will serve as a direct input to further strategic work on sustainable consumption policies. The aim of the report is to synthesize existing knowledge about the effects achievable with nudging on consumption and the environment, in what areas nudging according to research can have the best effect and how nudging should be applied to give the best effect. The study comprised a literature review and interviews to collect experiences of working with nudging available in some countries.
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A tool for sustainable behaviour?
A tool for sustainable behaviour?
Oksana Mont, Matthias Lehner and Eva Heiskanen
Phone: + 46 (0)8-505 933 40
Fax: + 46 (0)8-505 933 99
Address: Arkitektkopia AB, Box 110 93, SE-161 11 Bromma, Sweden
The Swedish Environmental Protection Agency
Phone: + 46 (0)10-698 10 00, Fax: + 46 (0)10-698 10 99
Address: Naturvårdsverket, SE-106 48 Stockholm, Sweden
ISBN 978-91-620-6643-7
ISSN 0282-7298
© Naturvårdsverket 2014
Print: Arkitektkopia AB, Bromma 2014
Cover photo: Oksana Mont
Cover illustration: Johan Wihlke
Printed Matter
Nudging – A tool for sustainable behaviour?
This study was conducted as part of a government commission which was
given to the Swedish Environmental Protection Agency (Swedish EPA) in 2014.
The Environmental Protection Agency mandated the International Institute
for Industrial Environmental Economics (IIIEE) at Lund University to conduct
a research study on nudging. The study has served and will serve as a direct
input to further strategic work on sustainable consumption policies.
The aim of the report is to synthesize existing knowledge about the effects
achievable with nudging on consumption and the environment, in what areas
nudging according to research can have the best effect and how nudging should
be applied to give the best effect. The study comprised a literature review and
interviews to collect experiences of working with nudging available in some
Professor Oksana Mont has been the Project leader and responsible
for analysis and presentation of results. PhD student Matthias Lehner has
been responsible for collecting and preliminary screening of literature.
Professor Oksana Mont, Professor Eva Heiskanen and Matthias Lehner have
analyzed literature and conducted interviews, and are all three authors of the
report. Other researchers from the research group on “Sustainable consump-
tion and lifestyles” at the International Institute for Industrial Environmental
Economics (IIIEE) have performed particular tasks, e.g. providing expert input
on specific approaches for changing consumer behaviour and on policy rele-
vance of behavioural economics.
From the Swedish EPA Elin Forsberg, Project manager of the gov-
ernment commission on measures on sustainable consumption policies,
Tove Hammarberg, Senior research officer and Anita Lundström, Senior
Policy Adviser, have provided comments to earlier drafts of the report.
The latter has finally reviewed and piloted this report for publication.
The views expressed in this report are those of the authors and cannot
be cited as representing the views of the Swedish Environmental Protection
Agency. The report is also published in Swedish (ISBN 978-91-620-6642-0).
The study has been funded by the Swedish Environmental Agency´s
Environmental Research Grant.
Swedish Environmental Protection Agency, December 2014
Nudging – A tool for sustainable behaviour?
1.1 Why are we interested in nudge? 9
1.2 Purpose and RQs 10
1.3 Methods and delimitations 10
1.4 Audience 11
2.1 Definitions 12
2.2 Why nudge? 14
2.2.1 Two systems of thinking 14
2.2.2 Departures from rational economic model 15
2.3 Where to nudge? 17
2.4 Who nudges? 18
2.5 Philosophy of libertarian paternalism 19
3.1 Simplification and framing of information 22
3.2 Changes to physical environment 25
3.3 Changes to the default policy 26
3.4 Use of social norms 27
4.1 Strengths of nudging 29
4.2 Weaknesses of nudging 30
4.3 Opportunities of nudging 31
4.4 Threats of nudging 32
5.1 USA 34
5.2 UK 35
5.3 EU 36
5.4 Denmark 37
5.5 Norway 38
6.1 Energy use in the home 39
6.1.1 Evidence for the effectiveness and efficiency 40
6.1.2 Critical success factors of nudging strategies 44
6.1.3 Lessons learned for devising more successful policies 45
Nudging – A tool for sustainable behaviour?
6.2 Food 47
6.2.1 Evidence for the effectiveness and efficiency 48
6.2.2 Critical success factors of nudging strategies 52
6.2.3 Lessons learned for devising more successful policies 53
6.3 Personal transport 54
6.3.1 Evidence for the effectiveness and efficiency 55
6.3.2 Critical success factors 59
6.3.3 Lessons learned for devising more successful policies 60
7.1 Designing policy interventions with behavioural insights 62
7.2 Nudge in the policy toolkit 66
7.3 Institutionalising nudge in policy context 67
Nudging – A tool for sustainable behaviour?
Success of strategies for solving problems of climate change, scarce resources
and negative environmental impacts increasingly depends on whether changes
in individual behaviour can and will supplement the technical solutions avail-
able to date.
A relatively new way to influence behavior in a sustainable direction with-
out changing values of people is nudging. Nudging can be used to help people
make choices that are better for the environment or their health. The impor-
tance of the behaviour change strategies is being recognised in politics and
among policy makers in diverse areas – from road safety to diet and physical
activity; from pension plans to private economy and from littering to recycling.
A renewed perspective on existing policy tools and potential strategies for
behaviour change are entering public debate that have implications for behav-
iour of individuals, but that also raise critical questions about the role of the
government in the society and transition to sustainability. Nudge means care-
fully guiding people behavior in desirable direction without using either carrot
or whip. Instead when nudging one arranges the choice situation in a way that
makes desirable outcome the easiest or the most attractive option. Knowledge
about nudging opens up possibility to suggest new types of policy tools and
measure that can contribute to sustainable consumption.
In many countries, public or private knowledge centers are engaged in
shaping nudging strategies and policy development. The report provides an
international outlook with experiences from the USA, the UK, EU, Norway
and Denmark. In the USA, nudging was institutionalised at the Office of
Regulatory Affairs which develops and oversees the implementation of gov-
ernment-wide policies and reviews draft regulations in several areas. In the
UK, nudge was firmly institutionalised when the Behavioural Insights Team
(UK BIT) was established at the UK Cabinet Office in 2010. In February
2014, the team was ‘spun out’ of government and set up as a social purpose
company but is still working primarily for the Cabinet Office. Instead of
establishing a governmental unit, Denmark has an active non-profit organisa-
tion iNudgeYou outside the government that supports the use of nudges in
policy making. Similarly to Denmark, Norway has an independent organi-
sation promoting and supporting the use of nudges, GreeNudge, which has
produced a report on the potential for nudging in Norway’s climate policy.
The guiding question is whether it is possible to help individuals make
better decisions for themselves and society at large by overcoming limitations
of human cognitive capacity and behavioural biases? In what way can behav-
ioural sciences help people bridge the gap between good intentions and good
deeds? Can learnings from nudge examples be used to shape behaviour in
a more sustainable direction?
Nudging – A tool for sustainable behaviour?
In order to answer these questions, the report:
analyses existing academic knowledge on nudging and choice architecture
investigates lessons about effectiveness and efficiency of applied nudging
tools and approaches in consumption domains of energy use in the home,
food and mobility
presents evidence of factors of success of different nudge-based approaches
outlines the implications of these findings for policy strategies on
sustainable consumption
The report shows that lately applications of behavioural sciences and behav-
ioural economics, such as nudge, have been helping policy makers in different
countries and sectors to more systematically integrate behavioural insights
into policy design and implementation. Some examples of these tools are:
Use default options in situations with complex information, e.g. pension
funds or financial services
Simplify and frame complex information making key information more
salient – energy labelling, displays
Make changes in the physical environment making preferable options
more convenient for people – e.g. change layouts and functions, showing
with steps and signs, give remainders and warnings of different kinds
to individuals
Use of social norms – provide information about what others are doing
However, the size of the effects of policy interventions and the actual outcomes
of interventions in specific contexts remain hard to measure. Results from one
experiment cannot be indiscriminately generalised to a different context or to
a wider population. The problem is the complexity of human behaviour and
the diversity of factors that influence it.
Despite that, nudging is a useful strategy for inducing changes in context-
specific behaviour. Rather than being seen as a silver bullet, the largest promise
of nudge is perhaps in helping design other initiatives better and in improving
the effectiveness and efficiency of policy tools and the speed of their implemen-
tation. Nudge is a cost effective instrument that can enhance other policy tools
and that targets behaviours not addressed by other policy instruments because
the behaviours are based on automatic, intuitive and non-deliberative thinking.
Nudging promotes a more empirical approach to policy design and evalu-
ation, e.g. through experiments, pilots and random control trials, than the
tools usually applied in policy making and ex-ante evaluation. Nudge tools
are seen as a complement to the traditional policy instruments rather than as
a substitute for laws and regulations and economic tools. Nudging in general
and green nudges in particular are interesting tools that can be used alongside
other instruments for behaviour change, but more research is needed on their
effectiveness and efficiency, as well as on their theoretical underpinnings and
practical applications in consumption-relevant domains.
The report is written for policy makers, civil servants and representatives
of the public, interested in behaviour change methods and the role of the gov-
ernment in shaping and facilitating the change.
Nudging – A tool for sustainable behaviour?
1 Introduction
1.1 Why are we interested in nudge?
There is a growing recognition that supply-side policies (directed at produc-
tion) need to be complemented by demand side strategies that could help indi-
viduals make better decisions for themselves and society at large. Therefore,
policy makers are becoming increasingly interested in applications of behav-
ioural sciences in different sectors and types of policy making.
Psychology, sociology, marketing and behavioural economics paint a picture
of complex human behaviour that is influenced by a diversity of factors, such
as desires and needs, social norms and values, infrastructural and institutional
context, and economic and political climate (Mont and Power 2013). There
is also a growing practical knowledge on how human behaviour is influenced
through everyday practices at home (Shove and Warde 2002), in the shopping
context by retailers (Mont 2013) or at the community and city level through
commercial advertising and social marketing (McKenzie-Mohr 2011).
Increasingly behavioural insights are being used in the design, implementa-
tion and evaluation of policy instruments (Heiskanen et al. 2009; Wolff and
Schönherr 2011).
Indeed, insights from behavioural sciences help policy makers not only
to better understand human behaviour and factors influencing behavioural
change, but to also devise more effective and efficient policies for advancing
welfare-enhancing and sustainable behaviour. Still, information provision and
labelling are the most widely used policy tools targeting individuals. They rely
on the rational behaviour model, according to which people are rational utility
maximisers with perfect information processing capacity. These assumptions
about human nature were questioned by cognitive and social psychologist
and even economists already in early 1950s–1960s. It was demonstrated that
people have bounded rationality, are subject to behavioural biases and often
do not make deliberate choices, but rely on mental shortcuts and habits.
These findings open up possibilities to design policies that recognise and
utilise knowledge of human behaviour as it is and not as projected in simplified
economic models. However, it has been difficult for psychologists to bring the
complexity of human behaviour into the policy making context and even more
challenging to translate it into the language of policy recommendations and
economic and administrative rationales. A book by behavioural economist
Richard Thaler and law scholar Cass Sunstein Nudge: Improving decisions
about health, wealth, and happiness (2008) has succeeded in popularising
some of the findings from behavioural science and their applications in policy
making. This spurred a renewed interest in employing behavioural sciences in
devising policies that enhance individual and social welfare. The book specifi-
cally explores the role of choice architecture and nudges in shaping behaviour
in a desired direction.
Nudging – A tool for sustainable behaviour?
These tools have been successfully applied by governments, for example in
savings accounts (Thaler and Bernartzi 2004) and public health campaigns
(Oullier et al. 2010). This gives reason to investigate the merits and limitations
of nudging and whether it can be a promising tool for promoting a broad
range of pro-environmental and sustainable behaviours.
This report analyses the existing evidence with regard to the role, limita-
tions and the varying degree of success of nudging in fiscal and social policy,
as well as environmental and consumer policy. It then describes potential
avenues for employing behavioural science in policy making and suggests
institutionalisation paths to ensure this. The report also identifies gaps in
knowledge that need to be addressed in future research.
1.2 Purpose and RQs
The goal of the study is to improve and increase the knowledge base of
Swedish policy makers and public officers on choice architecture and nudging
by answering the following questions:
1. What knowledge and practical experiences about nudging exist in general
and in the field of consumption and the environment?
2. In which consumption domains and behavioural contexts is nudging most
efficient and effective?
3. What are the critical factors of success of nudging strategies?
4. In what way may nudging contribute to devising more successful policies
for sustainable consumption?
1.3 Methods and delimitations
This study builds on literature analysis of the existing body of knowledge on
nudging approaches in different policy contexts, e.g. financial services, road
safety, health, diet, littering and recycling, social policy, and in consumption-
relevant domains, e.g. housing, mobility and food, as areas of the highest envi-
ronmental impact from households. The main focus of this study is on changing
the behaviour of individuals, where specific and concrete behavioural choices
are targeted. However, considering that many of the individual behaviours take
place in physical and social context and are often heavily influenced and shaped
by the infrastructure and institutional arrangements, or by what other people
are doing, both as individuals and as a group, individual behaviour change is
considered within the context in which the behaviour takes place.
The report relies on knowledge from European and North American
countries as cultures most closely related to the Swedish context and mentality.
The practical experiences with nudging instruments and tools are collected
from the UK and the USA, Sweden, Norway and Denmark.
Nudging – A tool for sustainable behaviour?
The results of the literature review were discussed with prominent nudge
researchers: 1) Prof. Cass Sunstein, USA legal scholar, the author of the
book Nudge: Improving decisions about health, wealth, and happiness,
2) Dr. Steffen Kallbekken, head of GreeNudge in Oslo, Norway and
3) Associate Professor Pelle Guldborg Hansen at iNudgeyou, Denmark
and Roskilde University.
1.4 Audience
The primary target audience for this report is policy makers, governmental
representatives and public servants working or intending to work with devising
and implementing policies that have direct or indirect implications for behaviour
change of individuals. Secondary target groups are other stakeholders, such
as non-governmental and civil society organisations and businesses, who are
interested in the role of policy in shaping and guiding behaviour change for the
benefit of the individual and the societal good. Additionally, the report might be
of use for the general public interested in gaining a snapshot picture of nudging.
Nudging – A tool for sustainable behaviour?
2 Choice architecture, nudge and
libertarian paternalism
2.1 Definitions
Mainstream economics, e.g. neoclassical economics, is based on the assump-
tion of the rational nature of human beings, i.e., the homo economicus model
of human behaviour. According to this logic, the important incentives people
react to are influenced by price and choice. Behavioural sciences, drawing
on insights from cognitive1 and social2 psychology, stress that besides price
and availability of options, behavioural biases and the decision context also
influence choices that people make, often routinely. For a long time, the use
of findings of behavioural sciences in policy have been rather unsystematic
(Shafir 2013). Behavioural economics has “managed to bring the fields of
applied social and cognitive psychology into policy-making by relating it to
economic questions” (Kahneman 2013).
In behavioural sciences, the decision context – the environment in which
individuals make choices – is important and is what Sunstein and Thaler
(2008) refer to as “choice architecture”. Altering the social and physical envi-
ronment or changing the way options are presented to people may increase
the chances that a particular option will become more attractive, a preferred
or even default choice. In the book “Nudge”, the authors use the example of
a cafeteria, where different types of foods are placed in different order and
this has implications for what food customers choose (Thaler and Sunstein
2008). Thus by changing the layout of the store or the order of the placement
of food in a cafeteria, choice architects may influence peoples’ behaviour.
From this perspective, every situation represents some kind of choice architec-
ture, even if it is not explicitly designed that way (Kahneman 2013).
Such aspects of the environment or elements of behaviour architecture
have been coined ‘nudges’. They are designed based on insights from cognitive
and social psychology and lately behavioural economics. The instruments
rely heavily on the idea of choice architecture that may include changes in
infrastructure or the environment that guide and enable individuals to make
choices almost automatically, where information provided is simplified or
where defaults are offered in a way that makes people better off. Thus, nudges
do not try to change one’s value system or increase information provision;
instead they focus on enabling behaviours and private decisions that are good
for the individuals and often for the society as well.
1 Cognitive psychology studies mental processes such as language use, memory, attention, problem
solving, creativity and thinking.
2 Social psychology investigates the factors and conditions that influence our behavior in a certain way
in the (actual, imagined or implied) presence of others.
Nudging – A tool for sustainable behaviour?
The term “nudge” was first used in the context of behaviour change by the
authors of the book “Nudge”, who define it as (Thaler and Sunstein 2008: 8):
“... any aspect of the choice architecture that alters people’s behaviour in
a predictable way without forbidding any options or significantly changing
their economic incentives. To count as a mere nudge, the intervention must
be easy and cheap to avoid. Nudges are not mandates. Putting the fruit at eye
level counts as a nudge. Banning junk food does not”.
So according to the authors, the primary aim of nudges is to guide people’s
behaviour towards better choices, as judged by themselves, without restricting
the diversity of choices. This definition has been debated in scientific circles as
being too broad and imprecise. An alternative definition has been offered by
the leading Danish behavioural researcher Hansen (2014: 2):
“A nudge is … any attempt at influencing people’s judgment, choice or
behavior in a predictable way (1) made possible because of cognitive biases in
individual and social decision-making posing barriers for people to perform
rationally in their own interest, and (2) working by making use of those biases
as an integral part of such attempts”.
As people are often unaware of the effects that changes in the environment
or different options have on their actions, nudges mostly work on changing
non-deliberative aspects of individuals’ actions (House of Lords 2011). Nudge
tools include defaults, working with warnings of various kinds, changing
layouts and features of different environments, reminding people about their
choices, drawing attention to social norms and using framing in order to
change behaviour. Coercive policy instruments such as laws, bans, jail sentences
or economic and fiscal measures, e.g. taxes or subsidies, are not nudges
according to Sunstein (2014b).
Whether provision of information is a nudge or not is being debated in
existing literature. According to Sunstein “provision of information is cer-
tainly a nudge, but it may or may not qualify as paternalistic3” (Sunstein
2014c: 55). Other researchers exclude openly persuasive interventions – media
campaigns and information provision – from the range of tools under the
umbrella term of nudge. However, according to them information provision
could be a nudge, especially if the goal is not just to provide as much informa-
tion as possible, but rather to simplify information so as to facilitate benign
choices, as for example in case of labelling or simplifying information about
financial services (Ölander and Thøgersen 2014). Other researchers argue
that information provision per se is not a nudge (Hansen 2014).
Nudges have been used by businesses in their marketing and sales promo-
tion for a long time. Also governments have been nudging people’s behaviour
change in different areas, perhaps without defining or framing policy instru-
ments as nudges. Now, however, nudges are being explored by governments
in a number of countries as a promising policy tool in the policy package for
behaviour change management.
3 Paternalism generally refers to a principle that entitles one (a person, organisation or state) to make
decisions instead of others for their own good.
Nudging – A tool for sustainable behaviour?
2.2 Why nudge?
Human behaviour is complex. Devising policies that entail or imply behavioural
change requires solid understanding of how people behave in different situa-
tions and contexts. Below some of the insights from behavioural sciences and
behavioural economics are outlined that explain how developing policy tools,
such as nudges, could help reduce behavioural biases and lead to choices that
are better for individuals.
2.2.1 Two systems of thinking
One of the important contributions to understanding human behaviour has
been made by a Nobel prize winner Daniel Kahneman (2011) who described
two systems of thinking: System 1 – fast (automatic, intuitive) and System 2
– slow (deliberate, conscious). While System 1 guides large parts of our daily
routines, which we do almost automatically, e.g. taking a shower or riding
a bike, System 2 relies on a much greater deliberate mental effort when we
need to make decisions about important choices in life. Thus, System 1 relies
on heuristics (rules of thumb), mental shortcuts and biases, and System 2
employs detailed multi-criteria evaluations, e.g. when people buy cars or
houses. So what does this have to do with policy?
The majority of existing policy tools for changing behaviour target System 2
that relies on the availability of information and our cognitive capacity to pro-
cess it and make rational choices. These tools are often guided by the assump-
tion that it is the lack of information or misguided incentives that are the main
reasons why people do not act rationally or even according to their own
preferences – the so-called attitude-behaviour gap. In order to bridge the gap,
policy makers use information provision such as awareness raising campaigns,
eco-labelling or other measures. Numerous studies however demonstrate that
providing information does not necessarily lead to changes in behaviour: all
people are aware of the harmful effects of smoking and yet a substantial share
of the population smokes. More than four out of five Nordic citizens are con-
cerned about the environment, yet only about 10–15% state they buy green
products on regular basis, while the actual market for green products remains
at only 3,6% in Sweden (Ekoweb 2013). Explanations to this gap found in
multi-disciplinary literature range from the power of habits and established
social norms to the complexity of decision-making process and infrastructural
and institutional lock-in effects (Mont and Power 2013).
Behavioural sciences and behavioural economics in particular challenges
the assumption of rationality and seeks explanations in the workings of
System 1 and System 2. Existence of System 1 means that in order to change
behaviour we do not always need to change minds. Secondly, although infor-
mation is important, it is not sufficient on its own to change behaviour, which
is to a large extent automatic, routinised and intuitive and is not affected
by the information per se. So what are the specific features of System 1 and
System 2?
Nudging – A tool for sustainable behaviour?
Table 1 Two systems of human thinking (van Bavel et al. 2013)
System 1 (Fast, intuitive) System 2 (Slow, reflective)
Regulates automatic behaviour
Thinks fast
Uncontrolled, unconscious, effortless
Relies on stereotypes
Gives immediate responses to frequent
and familiar situations
More prone to biases and heuristics
Examples: driving a car, brushing teeth
Regulates reflective behaviour
Thinks slow
Controlled, self-aware and effortful
Solves problems through calculation and deliberation
Takes well-thought out decisions
Less prone to biases and heuristics)
Example: calculating a tip, planning the day
2.2.2 Departures from rational economic model
Different branches of behavioural science, e.g. psychology, sociology and behav-
ioural economics, demonstrate that people do not always behave rationally in
the sense that they always maximise their utility. In fact, daily behaviours sys-
tematically violate the idea of the “rational” homo economicus. Indeed, people
often make decisions that are not in their best interest because they procrasti-
nate or lack self-control, because they are greatly influenced by the context in
which decisions are made, or because they are overwhelmed by the information
and have difficulties to make decisions (Reisch and Gwozdz 2013). Let us have
a brief look at some of the “anomalies” of human behaviour that each of us
exhibits every day and that can potentially be targeted by nudge tools.
Prospect theory by Kahneman and Tversky (1979) has highlighted the
endowment effect, according to which if people already possess something
they are very reluctant to lose it. This means that it is more important to
us to keep or hold on to something than to gain something.4 For example,
loosing SEK 100 causes more pain than receiving SEK 100 causes pleasure
(Kahneman and Tversky 1979). Studies show that our “willingness-to-accept”
can be up to 20 times higher than the “willingness-to-pay” (Pearce 2002).
In the public policy realm this translates into devising policies that emphasise
losses and encouraging people to take action to prevent loss from occurring.
Psychological discounting is another trait of our behaviour that means
that we place more weight on the short-term rather then the long-term con-
sequences of our decisions, thereby often discounting the future (Frederick
and Loewenstein 2002). In terms of consumption, people often overweigh
short-term gratification and discount the higher long-term gains that might
be achieved if we delay immediate consumption (O’Donoghue and Rabin
1999). For example, people tend to ignore the long-term effects of smoking,
poor diet or lack of exercise and are reluctant to save for retirement.
People also have limited computational capacity in decision-making situa-
tions especially when calculating probabilities, the so-called “availability bias”.
4 The large storage industry in the USA is built on that cognitive bias: due to high fees for storing stuff
($99–195/month) the payment for storing goods exceeds the value of the stored items after 6–8 months.
This faulty logic on the part of consumers, makes perfect sense for the industry, which has a collective
$20+ billion in annual revenues (SSA 2012).
Nudging – A tool for sustainable behaviour?
We tend to worry too much about unlikely events, but underweigh high prob-
abilities, the so-called “certainty effect” (Dawnay and Shah 2005). People also
tend to overestimate the likelihood of events that we remember well, which
can be affected by how recent our memories are or how emotionally charged
they are. This effect makes the role of the media, NGOs and other actors that
shape the information environment extremely important as they greatly influ-
ence the decision context.
People also desire to maintain status quo (Samuelson and Zeckhauser
1988). We could be overwhelmed by information, have limited time and
resources and thus prefer not to change our behaviour or habits unless we
absolutely have to. Information overload is one of the common reasons for
people’s inaction. A possible solution for policy action is to offer defaults that
maximise individual utility and/or social welfare.
Another aspect of human behaviour, recognised by psychologist Festinger
(1957) is cognitive consistency, i.e. people seek consistency between their
beliefs and their behaviour. However, when there is a mismatch between
beliefs and behaviour – so-called cognitive dissonance, people often alter their
beliefs rather than adjusting the behaviour. To help people be more consistent
some authors suggest soliciting commitments from people (Dawnay and Shah
2005), so that they feel more motivated to adopt their behaviour in order to
back up their stated beliefs, especially when commitments are made in written
or in front of other people.
The above-mentioned traits of human nature focus on the individual level.
However, since people are social beings, our behaviour is greatly affected
by what others are doing. For example, the famous “keeping up with the
Joneses” notion highlights the fact that people compare themselves to their
peer group. Social influence can be expressed through the idea of relative
income, when people are happy with their increased salary until they learn
that their colleagues received a higher raise.
There is also a well-known bandwagon effect – the tendency to do or
believe things because many people do or believe in the same thing (Colman
2003). Social psychologists stress that interpersonal, community and social
influences play an important role in shaping individual behaviours. They
highlight that people not only compare themselves to others, they also tend to
look for social cues of behaviour in new situations or circumstances (Cialdini
2007). Thus, social learning is an important feature of human life, i.e. we
learn by observing what others are doing and how (Bandura 1977).
Theories of inter-group bias highlight the importance for people to identify
themselves with certain group, expess loyalty and form identity associated
with certain social formations, whether it is community-based group, group
of colleagues or friends (Tajfel et al. 1971). People who belong to a certain
group tend to emulate the behaviour of members of that group. Therefore,
policy tools that exploit these inter-group biases and loyalties can encourage
peer support and community-based schemes.
Nudging – A tool for sustainable behaviour?
2.3 Where to nudge?
So for what behaviours are nudge instruments usually applied? Thaler and
Sunstein (2008) suggest that nudges are appropriate when choices have
delayed effects, when they are complex or infrequent and thus learning is not
possible, when feedback is not available, or when the relation between choice
and outcome is ambiguous. On the other hand, they provide many examples
from situations where no choice is actually made, and where it is more appro-
priate to speak of routine or habitual behaviours than active decision making
choices. According to Verplanken and Wood (2006) about 45% of our every-
day actions are not really choices at all, but habits or routines. For example,
people do not usually “choose” to leave the lights on when leaving a room or
to accelerate heavily when driving a car. People might not see themselves as
“choosing” to over-eat the wrong kinds of food, such as sausages or cookies,
either. People often succumb to bad habits in spite of having made an explicit
choice to avoid these behaviours, since behaviour is error-prone (Thaler and
Sunstein 2008) and not always within our control (Elster 1979/1984). Thus,
it is clear that a large portion of our behaviours are not actively reflected upon
and this is the primary application area for nudges.
On the basis of this analysis, we suggest that “nudge” interventions are
most appropriate in what marketing researchers call “low-involvement” deci-
sions, i.e., ones that involve little conscious deliberation, and also in high-
involvement decisions that are complex or unfamiliar (Figure 1). However,
it is not self-evident that nudges are likely to work (even in principle) in the
case of high-involvement decisions that are perceived to have low complexity.
Examples of such decisions where (at least individual, one-off) nudges might
not be effective could be the choice of a car brand in the case of people who
have high brand loyalty.
LOW involvement
Habitual behaviour
Perceived complexity:
Perceived complexity:
Figure 1 Areas in which nudge is likely to be most effective (indicated with YES)
Nudging – A tool for sustainable behaviour?
Attempts to influence values or attitudes are not part of the nudge paradigm.
Indeed, nudges can be seen as complementary or even tangential to interven-
tions focusing on attitude or value change. However, there is evidence that
suggests that nudges are likely to be more effective if they are perceived of
as legitimate (i.e., helping people to do what they ideally would like to do)
or when they are so unobtrusive as to be virtually invisible. This is based on
research from the USA (Costa and Kahn 2010; Hardisty et al. 2010; Gromet
et al. 2013), where politically conservative, anti-environmentalist consum-
ers responded to environmentally oriented labelling nudges differently than
politically liberal, more environmentalist consumers. This research suggests
that some nudges do not completely “bypass” information processing, but
are actually processed at some level. Hence, nudges might encounter less
resistance when they are in line with our ideal choices and values; and if they
build on these values, they might be more effective. Moreover, Ölander and
Thøgersen (2014) argue that many interventions that Thaler and Sunstein
(2008) call nudges actually also involve some active information processing.
Nudges might thus also form part of a broader package of instruments, where
information provision and persuasion might still have a complementary role
(Rasul and Hollywood 2012; Ölander and Thøgersen 2014).
2.4 Who nudges?
The term “nudge” usually refers to the the use of nudging as a tool to pro-
mote behaviour that is beneficial for individuals or society as a whole, and is
applied by policy makers to increase policy effectiveness. Policy makers can
use nudging in two ways, 1) to counteract the negative impact of other actors’
(e.g. business, media) attempts to subconsciously influence human behaviour
and thus reduce behaviour deemed undesirable (e.g. consumption of fatty,
salty and sugary food), and 2) to promote certain behaviour and thus increase
behaviour deemed desirable (e.g. consumption of healthy food) (Reisch and
Oehler 2009).
Businesses have a long tradition of applying diverse strategies similar to
nudge for shaping purchasing patterns and levels. Indeed, companies have
been pioneers in using insights from research on consumer behaviour, includ-
ing the latest developments in sensory techniques and neuro-marketing5, for
developing communication strategies in shops, marketing campaigns using
different channels outside the in-store environment and shaping buying behav-
iour through in-store space layout and management. In the words of Vance
Packard from the book The Hidden Persuaders (Packard 1957/2007: 11): “…
many of us are being influenced and manipulated—far more than we realize—
in the patterns of our everyday lives. Large scale efforts are being made, often
5 Neuromarketing is a new field of marketing research that studies consumers’ sensorimotor, cognitive,
and affective response to marketing stimuli.
Nudging – A tool for sustainable behaviour?
with impressive success, to channel our unthinking habits, our purchasing
decisions, and our thought processes by the use of insights gleaned from
psychiatry and the social sciences.”
In response to public pressure and consumer attention, companies have
shown to be willing and able to use their knowledge about human behaviour
to nudge individuals in a desirable direction. More and more companies, for
example, are reacting to strong public attention for sustainability and are
trying to create and promote markets for environmental and socially sound
products (Maniates 2010; Moisander et al. 2010). It must be remembered,
though, that while it might seem that marketing and nudging have much in
common or that the two strategies are the same thing, there is one vital dif-
ference between the two approaches in that while nudge presupposes helping
people make choices that are good or beneficial for the people and society,
marketing aims to entice people into choices that primarily bring about
benefits for businesses (Table 2).
Table 2 Traditional marketing vs. choice architecture and nudge
Traditional marketing Behavioural economics and nudge approaches
Traditional marketing
Aims to first of all maximise profits and
benefits of businesses
Focus on what needs to be sold, not necessar-
ily on the best alternative for consumers
Reliace on marketing experts (including
behavioural experts) in corporate
Choicearchitecture and nudge
Aims to first of all benefit people/
Focus on options that are best for people
leaving possibility for people to opt-in or opt-out
Reliace on behavioural experts in the process
of policy planning
This of course does not mean that win-win solutions that benefit both businesses
and provide consumer welfare are impossible. Retailers may promote green
products, low-fat diets and customised nutritional advice that benefit both
their customers and generate profits for the business. It does mean, however,
that one must remain careful about business’ interest to engage in nudging
(maybe even on behalf of the government). Nevertheless, governments can
harness the power of private business to nudge certain behaviours through
regulatory means or financial incentives. For example, businesses can be
required by the government to nudge people’s behaviour in certain direction
by designing choice architectures in specific ways, e.g. by offering defaults in
pension plans or health insurances.
Other actors, e.g. NGOs, may and do apply nudges in order to influence
people’s behaviour for their own good, e.g. (Duflo et al. 2011).
2.5 Philosophy of libertarian paternalism
The nudge concept builds on the notion of “libertarian paternalism” (Sunstein
and Thaler 2003) – a policy approach that preserves freedom of choice (i.e.
libertarianism), but encourages the public sector to steer people in directions
Nudging – A tool for sustainable behaviour?
that will promote their own welfare (i.e. paternalism). People are allowed to
make choices, but the choice architecture is designed to promote the desired
So is there a legitimate role for the government in seeking to change people’s
behaviour? In principle it is accepted in society that a government develops and
pursues policies that benefit the society at large and its people. Thus, govern-
ments provide conditions in which individuals can maximise their utility, but
also shape institutions and infrastructures that enable and make it easy for
individuals to realise individual benefits. While some policy interventions
are of a more generic nature, such as sustainability or climate change, others
aim to assist people in avoiding certain individual problems, such as obesity,
alcohol consumption or smoking. Such private matters are of concern for the
government since unhealthy lifestyles result in increasing public spending on
healthcare services and therefore the government has legitimacy and in fact
a responsibility to promote healthy lifestyles. Following similar argument,
individual actions, such as driving, may have adverse aggregate impacts on
the society and could therefore be targeted by the government.
Libertarian paternalism has been defined as “…a relatively weak, soft
and nonintrusive type of paternalism because choices are not blocked, fenced
off, or significantly burdened [...] better governance requires less in the way
of government coercion and constraint, and more in the way of freedom
to choose. If incentives and nudges replace requirements and bans, govern-
ment will be both smaller and more modest” (Thaler and Sunstein 2008: 5
& 14). Successfully deploying the philosophy of ‘libertarian paternalism’ can
be understood as a means to avoid more authoritarian forms of paternalism
(Reisch & Oehler 2009).
There is an ongoing discussion regarding the ethics of libertarian paternalism,
with specifically two issues being heavily debated: the intrusiveness of govern-
mental rule in people’ lives and the transparency of nudge tools undertaken.
Nudging as an idea emerged in the USA, a country that historically builds on
a profoundly different approach to the freedom to choose vs. protection from
bad choices compared to the tradition in many European countries, including
Sweden, see (Frerichs 2011). As a consequence, while for the American audi-
ence nudging means more paternalism in societal and market liberalism, for
Sweden in many cases it may mean more liberalism in state paternalism. This
must be kept in mind when one discusses nudging in specific social contexts.
It can be assumed, for example, that nudging is promoted as desirable from
an American perspective where more stringent interventions in individual
choice are politically unacceptable. However, an even better solution might
be identified in a regulatory intervention, which – even though impossible to
implement in the USA – might be fully possible in Sweden, see (Cronqvist and
Thaler 2004).
The transparency of nudge tools is discussed because nudges influence
non-deliberative, automatic and intuitive processes of thinking and making
choices through mechanisms of which people might not be aware (House
Nudging – A tool for sustainable behaviour?
of Lords 2011). Governments may face different levels of public acceptance
depending on whether they take a paternalistic approach in terms of the
means (policy tools and measures) or the ends (goals of intervention). For
example, even if a government is justified in taking measures to address a cer-
tain problem (i.e., the ends are accepted), the measures (the means) themselves
might not be accepted by the public as ethically justifiable due to the degree
of intrusion into everyday life or due to the extent to which the measure is
non-transparent or even concealed. There is an opinion that the most intrusive
interventions need to be justified most vigorously and be used with utter care
as they may limit or edit out choice (House of Lords 2011).
Therefore interventions need to be proportionate to the gravity of the
behaviour and its impacts they are trying to change. However there is no
solid method for how to weigh the proportionality. The British government
for example has focused on interventions that enable and encourage a certain
choice rather than restrict it. Indeed, some researchers advocate the govern-
ment to use nudge when it is used as “facilitator”, i.e. making behaviour and
choices easier, and much less when it is used as “friction”, e.g. making choices
or behaviour more difficult or limiting the choices (Calo 2014). They argu-
ment this position by the fact that nudging when used by the government
lacks the usual safeguards that accompany law making.
Therefore, the issue of transparency of nudge instruments becomes critical.
Nudge has been accused of being manipulative and some authors warn against
the real risk of the government abusing the power of nudge (Hausman and
Welch 2010). It is discussed that it is in the interest of the government to ini-
tiate an open societal dialogue in a true democratic manner about the use of
nudge instruments for pro-social and other purposes. It is said to be important
that nudged consumers know the types of interventions that are being applied
and that they are capable of identifying them if they would like to.
Nudging – A tool for sustainable behaviour?
3 Nudge toolkit
Nudge is a collective term for different policy tools that policy makers can use
in order to influence individuals’ behaviour. Table 3 categorises various policy
tools, including nudging, based on how they influence the choice of individuals.
Table 3 Policy tools to influence individual behaviour based on (House of Lords 2011)
Regulation of
the individual
Fiscal measures directed
at the individual
Non-regulatory and non-fiscal measures with
relation to the individual
Eliminate and
restrict choice Guide and enable choice
Incentives and information Nudging
Laws and
Fiscal incentives
Provision of
and framing of
Changes to
Changes to the
default policy
Use of social
The most intrusive to individual freedom tools – laws and regulations – are
found on the left of the table. Then follow fiscal tools (e.g. taxes, subsidies)
that provide economic (dis-)incentives to individuals. The third group of inter-
ventions comprise tools that are non-regulatory and non-fiscal. Among those
are non-regulatory and non-fiscal incentives, and information provision to
enable consumers make informed choices.
Finally come four types of policy instruments that together constitute
‘nudging’. Unlike the aforementioned instruments that mostly draw on the
neoclassical economics idea of the ‘rational man’, nudging instruments rely
on a more nuanced picture of behaviour offered by such behavioural sciences
as cognitive and social psychology and sociology, based on which changes
in behavioural architecture and context are made, that influence behaviour.
Nudging comprises four types of tools: 1) simplification and framing of infor-
mation, 2) changes to the physical environment, 3) changes to the default
policy, and 4) the use of social norms.
3.1 Simplification and framing of information
Nudging builds on the insight that not only the amount or the accessibility
of information provided to people matters,6 but also how this information is
presented. The complexity of information affects greatly the outcomes of deci-
sions people are making. Simplifying information and understanding in which
context it is presented (e.g. what comes before and after the information) may
drastically change people choices. John et al. (2013: 9) state that “[n]udge
6 Both of which are central to ‘economics of information’ literature
Nudging – A tool for sustainable behaviour?
is about giving information and social cues so as to help people do positive
things for themselves and society”. Simplification means that information is
made more straightforward and presented in a way that fits best to the infor-
mation processing capabilities and decision-making processes of the individual.7
Simplification is especially of value in complex products or services, e.g.
financial or investment decisions, when people often struggle to make benign
choices even in the most simplified of the environments.
The framing of an issue is also important. Framing is the conscious phrasing
of information in a way that activates certain values and attitudes of individuals.
“Framing essentially involves selection and salience. To frame is to select some
aspects of a perceived reality and make them more salient in a communicating
text, in such a way as to promote a particular problem definition, causal inter-
pretation, moral evaluation, and/or treatment recommendation for the item
described” (Entman 1993). Often, simplification and framing happen simulta-
An example for how framing of choice influences both behavior and even
experience is reported by Wansink et al. (Wansink et al. 2001). They studied
the effect of renaming menu items in a school cafeteria. They called the most
popular food items either plainly informative (e.g. ‘Zucchini Cookies’) or
descriptive (e.g. ‘Grandma’s Zucchini Cookies’) and found that descriptive
labels increased sales by 27%. They also found that the use of descriptive
labels increased post-trial perception of quality and value of the product and
that descriptive labels increased customers’ intention to return to the cafeteria.
Another typical example of information simplification and framing is food
labelling. It often focuses on health and environmental aspects of food and is
designed to help make choices to counteract lifestyle-related health problems,
e.g. obesity, diabetes, etc. (Rothman et al. 2006). Further changes in food
packaging are discussed with one popular suggestion being a ‘traffic light
system’ of information provision intended to frame the consumer decision
in line with learned-in reactions to traffic lights (i.e. red is bad, green is good),
e.g. (Sacks et al. 2009).
Another example is re-framing of a message that encourages purchase
of food products that are close to best-before date to avoid food losses. The
largest Swedish food retailer ICA has noticed that consumers interpreted the
red price reduction sticker on such food items was associated with low quality
and potential health hazard. ICA Maxi Södertälje tested to put instead a green
sticker and to change the text from “Lower price” to “Lower price – eat soon.
This product is approaching expiration date but is still fresh. Buy it and you
will save the environment and money”. The retailer judges the outcome as
positive and the initiative has spread to other stores within ICA (Chkanikova
and Lehner 2014).
7 For an extensive summary of tools to simplify and customise information see Johnson et al. 2012
Nudging – A tool for sustainable behaviour?
The EU’s mandatory labelling scheme for electrical appliances can also be
seen as an example of information simplification. Introduced in 1995, the
EU regulates how the information regarding energy consumption of electrical
appliances is to be presented (Ölander and Thøgersen 2014). The label makes
considerations about energy efficiency more salient for consumers at the point
of purchase.8
Thaler and Sunstein (2008) suggest that
labels could be even more useful if they trans-
lated energy or fuel use into cost per annum
(compare the EU and the U.S. labels below).
Another way to simplify and frame infor-
mation is through feedback. Thaler and
Sunstein (2008) stress that it is often impor-
tant to provide immediate feedback to people
about the mistakes and ways to avoid them
in order to make information effective.
Timely and effective feedback can enable
people to realise implications of their actions.
For example, installing an energy use meas-
uring device could provide feedback on how
efficient various energy-using devices are. The
energy metering device could be equipped
with light and sound function to warn people
about peak hours or when their electricity
consumption is increasing so that they could
take measures to reduce it and avoid unnec-
essary costs. Another good example comes
from Malmö’s waste management company
Sysav that provides monthly newsletter to
inhabitants where information is presented about different waste streams from
households and on the results of food waste sorting in the previous month,
linking the kilograms of collected sorted food waste to the amount of biogas
produced from it and to the number of Malmö busses that run on that biogas.
This newsletter does more than just providing information: it links the actions
of individuals to the common good in the local context that people can relate
to; it makes people feel that they belong to the social group of people who are
separating food waste; and it highlights the reward to everybody from sorting
out food waste as the public busses run on clean fuel and thus environmental
pollution in the city is reduced.
8 Source:
Figure 2 EU Energy label for
Nudging – A tool for sustainable behaviour?
3.2 Changes to physical environment
The physical environment has long been acknowledged to have significant
impact on individuals’ choices. Especially in low involvement decision-making
situations individuals are likely to allow the physical environment to influence
their choices, as for example in the retail store where people make daily pur-
chases. For example, Nordfält (2007) describes how consumers are guided
through the retail store to increase the total volume or number of items
bought or to maximise the procurement of some goods over the others. Have
you noticed that milk – one of the most often purchased food products – is
situated furtherst away from the entrance, making people to go through the
entire store and perhaps pick up items on the way that might not be on their
purchasing list. Another way to nudge people into buying certain products is
by careful selection of their place on shelves – most sold products are situated
at the eye level. Also products that are situated closest to cashier are the ones
that are often sold. So if a store places fruits close to cashier then people will
buy more fruits than if sweets are placed there and visa versa (Goldberg and
Gunasti 2007). Nordfält (2007) also discusses the impact of smell and sound
in the retail environment. Both appear to have an impact on the emotional
state of human beings, and thereby influence shopping choices.
Numerous studies have also been conducted on the impact of the design
of the eating environment, e.g. canteens and restaurants. Thaler and Sunstein
(2008) describe the impact of placing meals in different order or of positioning
healthy foods at the eye height. Even some environmental factors have impact
on the amount and type of food consumed. For example, plate size has contin-
uously increased in recent history (Wansink and Wansink 2010), and has been
linked to increasing levels of obesity. It has been shown that reduced plate size
in all-you-can-eat environments (Freedman and Brochado 2010) and reduced
portion size (Rolls et al. 2002) both reduce total energy intake and food waste.
A similar study of reducing plate size from 24 to 21 cm among guests of 90
Nordic Choice Hotels found that, on average, food waste was reduced by
15% (Kallbekken and Sælen 2013).
Figure 3 Reduced plate size led to less food waste. Photo:A-Lundström
Nudging – A tool for sustainable behaviour?
Many studies are available on the role of the physical setup of the recycling
system for the success of recycling efforts. Specifically the availability of recy-
cling facilities, their attractive design, clear guidance and convenience for users
have been identified as success factors (Oskamp et al. 1996; John et al. 2013;
Park and Berry 2013).
In a recent study, Pucher and Buehler (2008) try to understand the most
significant factors behind an increase in cycling as means of transport in
Denmark, Germany and the Netherlands. They conclude that the most impor-
tant policies to increase the share of cycling in total transport is related to
changes to the physical environment. They suggest that the most important
policies are the provision of separate cycling facilities along heavily travelled
roads and intersections, traffic calming efforts in residential neighborhoods,
the provision of sufficient parking space for bikes, the integration of biking
with public transport and – more general – urban planning that focuses on
density and the prevention of city sprawling.
3.3 Changes to the default policy
People often take the path of least resistence, prefer not to act unless they have
to and procrastinate. Therefore they are greatly influenced by defaults, which
determine the result in case people take no action. For example, a single-sided
print option is unfortunately a default which contributes to much higher volumes
of paper than if default would have been double-sided copy. A Swedish study
demonstrates that 30% of paper consumption is determined by the default and
that by switching the default options paper consumption could be reduced by
15% (Egebark and Ekström 2013).
The importance and effectiveness of the default option is often illustrated
by the example of organ donation programs. In countries where the default
option is to be enrolled in an organ donation program (i.e. where consent
is presumed – the countries on the right in Figure 4), participation is signifi-
cantly higher than in countries where a person must actively choose to opt
into enrolling (i.e. give explicit consent – the countries on the left in the figure
below) (Johnson and Goldstein 2003).
Thaler and Sunstein (2008, p. 117) describe the case of pension saving
decisions. They claim that across the world individuals fail to sufficiently
save for their retirement and to take advantage of various government-sup-
ported schemes that are economically beneficial. They therefore suggest to
make enrolment of individuals into pension saving plans a default option with
the possibility to opt out of it.
Cronqvist and Thaler (2004) studied the design and results of the privati-
sation of the Swedish pension savings system in which people were encouraged
to choose their pension plan. If for some reason they failed to do so, there
was a default option defined for them. The experience was that those who
did not actively choose the pension plan generally were better off than those
who chose. The authors came to the conclusion that often the best outcome for
Nudging – A tool for sustainable behaviour?
most individuals is offered by a good default option, from which individuals
can opt out and choose their own plan. They also recommend that default
choices should be very limited and simplified in order for individuals to be
able to make an informed decision and to restrict the ability for marketers
to influence this choice. This is particularly true for complex choices such as
choosing an ideal fund composition for retirement saving as most individuals
are inexperienced and relatively illiterate when it comes to financial markets
and investment options.
Default options play a great role also in market interactions and marketers
often exploit human tendency to accept default options. For example, online
shopping is full of defaults that make people subscribe to additional services,
purchase products they were not intended to buy or choose automatic prolon-
gation of subscriptions of various kinds, which sometimes results in suboptimal
for the individuals outcomes, e.g. financial. Therefore Thaler and Sunstein
argue that it makes sense for policy makers not to leave the design of default
choices to chance or to actors with private interests, e.g. marketers, but to
instead make the design of default choices an active aspect of policy design,
see also (John et al. 2013).
Indeed, in the latest Consumer Rights Directive the EU has banned online
retailers from using pre-ticked boxes (e.g. for travel insurance in air travel) in
their choice and payment process (Lunn 2014).
3.4 Use of social norms
Since humans are social beings, social norms are a strong force that influences
human behaviour. Cialdini et al. (1990) talk about two ways in which social
norms affect the individual, 1) as injunctive norms, and 2) as descriptive
norms. The injunctive norms act upon the individual as a moral implication,
nited Kingdom
99,98 98 99,91 99,97 99,5 99,64
Figure 4 Effective concent rates, by country. Explicit concent (opt-in, gold)
and presumed concent (opt-out, blue) (Johnson and Goldstein 2003)
Nudging – A tool for sustainable behaviour?
i.e. what ought to be done and what ought not to be done. The descriptive
norms refer to the simple observation of how everyone or most others behave
(thus the “normal” way to do something), which is replicated by the individ-
ual who might be unsure about how best to act in a certain situation.
For the norm to make an impact on behaviour, it has to be salient – visible
– for the individual (Cialdini and Goldstein 2004). Cialdini et al. (1990) also
showed that when individuals are reminded of a certain norm the chance that
they follow this norm increases significantly. Cialdini et al. (1990) explain
that individuals often carry several norms for one and the same situation.
They derive these different norms from different social/cultural environments
they are familiar with, or from different aspects of one’s self-identity. In any
given choice situation whatever norm is most present in the individual’s mind
(i.e. most salient), will have the greatest impact on the behavioural outcomes.
Salience as a nudge factor can also be connected to framing, the conscious
phrasing of information in a way that triggers certain values and attitudes and
therefore increases the likelihood that a choice follows one set of norms and
not another (see above). An example of the effect of salience on consumption
was reported in a study that measured fruit consumption in two schools
(Schwartz 2007). In the first school cafeteria employees asked pupils “Would
you like fruit or juice to your lunch?”, while in the second school no such
verbal prompt was provided. The intervention resulted in 70% of the children
consuming a fruit at lunch in the first school compared to less than 40% in
the control school.
In another study, Goldstein et al. (2008) use the power of descriptive
norms to change the reuse rates of towels among hotel guests. They placed
the text “the majority of guests reuse their towels” in bathrooms and this
produced significantly better reuse results than information solely focused
on environmental protection. In another experiment – a real life observation
– a utility company in the USA has achieved energy savings between 1.4%
and 3.3% by mailing Home Energy Report letters to customers in which they
compare the customer’s energy use with that of similar neighbours and provide
energy conservation tips along the information that they are performing worse,
as good as or better than their neighbours (Allcott 2011: 1082).
Social norms play a role also in other areas, e.g. studies found that neigh-
bours’ recycling rates influence each other. John et al. (2013) point out that
this effect is most explicit in areas with high attachment of the individuals to
the neighbourhood, with a strong community spirit and with high peer pres-
sure. John et al. (2013, p. 45) explain: “most people underestimate the extent
of pro-social behaviour among their peers and then use those low estimates as
a standard against to judge themselves”. The study built on this insight and
conducted an experiment in which they provided people with feedback about
their street’s food waste recycling performance compared to other streets in
the area and a ‘smiley face’ or an ‘unhappy face’ depending on whether their
streets’ performance was better or worse than average. This intervention pro-
duced a 3% increase in food waste recycling compared to a control group.
Nudging – A tool for sustainable behaviour?
4 Nudge: SWOT
4.1 Strengths of nudging
The recent surge of interest in nudging is due to several strengths that make it
attractive to policy makers.
The most obvious strength of nudging is its compatibility with ideals of
the free market. In an age when ideological preference for free markets and
the increasing impact of globalisation on nation states limits policy makers’
ability to regulate and tax in order to influence individuals’ behaviour, nudging
is a practical and more acceptable approach for politicians to try to solve
pressing social and individual problems, e.g. (Thaler and Sunstein 2008).
Second, insights from psychology and behavioural economics on which
nudging builds help policy makers to relate complex policy making processes
and goals to individuals’ daily decision-making. Unlike in classical economic
theory, the understanding of human behaviour at the basis of nudge is derived
from empirical evidence rather than abstract theoretical models (Oullier et al.
2010). Nudging requires and enables policy makers to take into account
human behaviour in design and implementation of policies.
For the citizen nudging offers two advantages, 1) guidance in difficult
decision-making processes, and 2) the possibility to reject choices where they
are contrary to the individual’s preference or advantage. The first refers to
the limited rationality idea of human decision-making. While humans might
want to make good decisions for themselves, the cognitive limitations of the
human mind often make it difficult for the individual to make an informed
choice. The opportunity to rely on nudges designed by a well-meaning party,
i.e. democratically legitimised policy makers with one’s best interests in mind,
therefore might mean a relief to many individuals in certain situations (Iyengar
and Lepper 2000). Nudging therefore works particularly well where there
are immediate or at least short-term benefits for the individual, which make
advantages of nudge evident to the individual. At the same time, for any choice
some individuals are better equipped to make decisions than the average citizen
or a well-meaning third party and are thus more capable of making decisions
that is in their best interest. It is beneficial that in such situations nudging does
not impose a choice restriction upon the well-informed individuals as it enables
them to choose differently than intended by the choice architect.
The fact that individuals can opt out of the nudge also provides a safety
valve for occasions where the ‘well-meaning policy maker’ makes decisions
based on other interests than the individual’s (Cooper and Kovacic 2012).
This increases the chance for policy makers to positively influence the majority
of individuals while leaving a minority with the freedom to choose differently.
Nudge can furthermore allow people to test certain behaviour, which could
then be followed by changes in people attitudes, and thus it can be a potential
“gate opener” for stronger policy making (i.e. the introduction of fiscal and
regulatory policies; see Figure 10 – Ladder of interventions).
Nudging – A tool for sustainable behaviour?
4.2 Weaknesses of nudging
Nudging as a behaviour influence tool also has a number of weaknesses.
One of the main weaknesses is the difficulty to design a policy intervention
right and make sure that what works in a laboratory or intervention environ-
ment (as often used in scientific studies) also has the desired effect on a popu-
lation level. The problem is that there is a lack of evidence at a population level
since few applied research studies have had resources to work with an entire
population as a sample. There is also a lack of evidence on cost effectiveness
and long-term impact of many experimental studies (House of Lords 2011:
18–19). In addition, devising a choice architecture that successfully translates
results from lab environment to the level of population is time consuming
undertaking. The initial impact of nudging is therefore often small (Olstad
et al. 2014) and the choice architecture often has to be repeatedly adjusted in
a trial-and-error process before it satisfactorily achieves the desired outcome
(Kopelman 2011).
Another weakness with nudging is that humans, as reflective and self-
reflective beings, adjust and change their behaviour based on changes in their
environment. It is therefore difficult to be sure what different individuals (or
groups of individuals) make out of one and the same nudge (Marteau et al.
2011; Johnson et al. 2012). To be successful, nudging requires a high level
of understanding of the context of an individual’s decision-making process
(Olstad 2014). What might prove successful with one group of individuals
and at one point in time might loose its effectiveness over time. Wansink and
Chandon (2006), for example, found that ‘low fat’ nutrition labels lead con-
sumers – in particular overweight consumers – to overeat snacks. Ohlstad
(2014) therefore argues that nudging might be too subtle a technique to
counter the powerful impacts of other factors.
An additional problem for policy makers is that a nudge’s full potential
might be capitalised on after a certain adaptation period. Allcott and Rogers
(2014) describe an energy saving program in which the Californian utility
‘Opower’ uses energy reports to inform each individual customer about
their energy use and how their consumption compares to others. While the
initial effect of such reports is short-lived and fades soon after the report was
received, the effect becomes more long-lived over time. Allcott and Rogers find
that after such reports are received for two years, the effect remains strong for
a long time, with a rate of decay of 10–20% per year after individuals stop
receiving the reports.
To increase the success of nudging, Marteau et al. (2011, p. 264) argue
that nudging must be designed to take into account existing knowledge on
what works, for which group of people, in what circumstances, and for how
long one can expect results. To answer these questions for a large group of
heterogeneous individuals requires considerable resources and bears the risk
for policy makers to have to engage in sophisticated micro-management of
markets and society, with increasing risks for unintended side-effects or simply
for ineffective policies. It has, for example, been shown that energy saving
Nudging – A tool for sustainable behaviour?
nudges that work well with liberals in the USA, do not work with conserva-
tives (and might even have adverse effects) (Costa and Kahn 2010).
The complexity of implementing nudges at a societal scale has led some
authors to raise doubts about the potential of nudging to also contribute to
solving large societal problems, such as climate change, e.g. (Schlag 2010;
Goodwin 2012). Goodwin (2012, p. 86) writes “… nudging alone is not
an effective strategy for changing behaviour on the kind of scale needed to
solve society’s major ills”.
Finally, nudging has been criticised for placing too much focus on the
System 1 type of thinking – fast and automatic, while leaving the interaction
with System 2 unaddressed (Stoker 2012). This criticism is especially relevant
in consumption context since it has been suggested that long-term changes in
society towards pro-sustainable values require deliberative processes, societal
debates and conscious choices to be combined with automatic, intuitive and
routinised behaviours. It is considered unlikely that sustainability can be
sneaked in into everyday lives of people; it is more likely that we need people
to both think pro-sustainably and act pro-sustainably with the help of nudges
(John et al. 2013), but not rely on nudges alone.
4.3 Opportunities of nudging
Even though the complicated nature of human behaviour makes it difficult and
time consuming to implement successful nudge policies, a long-term strategy
for nudging can have significant impact. Allcott and Rogers (2012, p. 32)
claim that persistence in nudging can lead to cost effective achievements that
go beyond policy makers’ expectations.
It has been argued that modern Information and Communication
Technologies (ICT) will increase the effectiveness of nudging and make it
easier to customise nudging efforts to individuals. Baum (2011) reports on
already enfolding efforts by private business to support individuals in living
a healthy lifestyle. Baum identifies the smartphone – the ubiquitous and highly
personalised device – as important in this process. Most recently companies
have further started to develop the product category of ‘wearable devices’ (e.g.
smart watches). All these devices include an ever-increasing number of sensors
and sophisticated software, able to track, store and process data for analysis.
Baum (2011) argues that the general public increasingly accepts such devices
and the increasing familiarity with their functionality will increase their use-
fulness and sophistication. These devices offer a good platform for nudging
not only because they are capable of providing real-time information in user-
friendly ways, but also because the software often incorporates a social com-
ponent, e.g. offering the possibility to share and compare individual data with
one’s peer network or the overall user base. Baum (2011) describes ICT as
empowering to users to take responsibility for their own health.
Lanzarone and Zanzi (2010) further argue for the usefulness of ICT
to encourage more resource efficient behaviour in private households.
Nudging – A tool for sustainable behaviour?
They describe the spreading of smart meters, combined with homepages dis-
playing the collected information as a system that makes it easier for indi-
viduals to save, e.g. gas and water. They use an Italian example (the MICE
project implemented by the energy provider ENEL) to describe how nudging
can be easily implemented in such applications. The homepage of this project
offers consumers simplified information about their use (hourly consumption
data, graphical presentation of the data), the possibility to compare their con-
sumption with other consumers in the same client class, and a self-evaluating
questionnaire including suggestions about more efficient behaviour. The user
interface thus applies several nudge principles to influence consumer behaviour.
The usefulness of ICT to nudging individuals is obvious in many fields,
such as grocery shopping (e.g. the USA-based ‘GoodGuide’ mobile phone
app), food waste (e.g. the UK-based ‘Love Food, Hate Waste’ mobile phone
app), transportation (various ride sharing apps), or clothes sharing (e.g. the
start-up ‘Share Closet’).
It should be mentioned that nudging can be used as a direct policy tool,
with policy makers engaging in changing the choice architecture of individuals.
However, nudging can also be used indirectly by policy makers who may create
legal framework that will encourage other actors (such as businesses, NGOs,
civil society organisations, churches) to use nudges to direct individuals in the
desired behavioural direction. Such actors are more likely to naturally engage
in nudging, as they have little or no ability to force certain behaviour upon
individuals as governments have. They usually represent service sectors of
society, which allows them design nudges customised for special groups rather
than society as a whole.
4.4 Threats of nudging
Nudging has received criticism from law scholars for its potential danger
to the democratic processes at the basis of Western societies. Marteau et al.
(2011), for example, identify a danger in the implicit tendency to manipulate
people (or at least hold back information). Hansen and Jespersen (2013) try
to overcome this critique by distinguishing between transparent and non-
transparent nudges, of which only the first is deemed acceptable. However,
nudging often works best when individuals are not consciously aware of being
nudged. Where nudging happens on a conscious level – particularly where
it opposes personal behavioural intentions – the effect of changes in choice
architecture can be greatly reduced, see e.g. (Bronchetti et al. 2011; Ölander
and Thøgersen 2014).
Felsen (2013) further suggests that the subconscious approach to behaviour
change applied in nudging might lead to a backlash in citizens’ perception of
governmental efforts to change their behaviour and alleniate individuals from
a public behaviour change agenda, as they might perceive this approach as
manipulative and an infringement on personal autonomy.
Nudging – A tool for sustainable behaviour?
Nudging can also be understood as unfair. Especially where nudging is applied
by policy makers to achieve common goods (e.g. climate change mitigation),
there is a risk that these policies will allow a minority of well-informed citizens
to free-ride the efforts of the majority. Sunstein and Reisch (2013) claim that
nudging often works best on the uninformed and uneducated part of society. It
is democratically worrying to use nudging to influence the behaviour of those
not able to identify a nudge, while allowing those that are able to identify
it (and thus avoid it) can subcumb the costs while benefiting from the gains
(Goodwin 2012).
Connected to the above, there is a risk in that policy makers regard nudging
as an easy and comfortable way out of cumbersome and controversial attempts
to implement regulation and legislation (Bonell et al. 2011). Schlag (2010)
argues that the focus on preserving freedom of choice instead of adjusting the
choice architecture might undermine the use of more effective, but choice-
restricting policies. Discussing climate change, he claims that freedom of choice
often is not the primary goal to strive for; instead a reduction in total emissions
(to safeguard humankind’s future) must be the ultimate goal, regardless of how
this influences the freedom of choice of the individual.
Nudging – A tool for sustainable behaviour?
5 Nudge: how the work is
organised in various countries
5.1 USA
In the USA, nudging was institutionalised at the Office of Regulatory Affairs
(OIRA) at the White House (Lunn 2014). OIRA develops and oversees the
implementation of government-wide policies in several areas and reviews draft
regulations. Cass Sunstein, co-author of Nudge, was head of this office from
2009–2012. During this time, behavioural economics was used to introduce
better testing of old regulation and monitoring systems for new regulations.
Examples of regulatory reforms in the USA that have drawn on behavioural
economics are credit card regulations and Obama’s Affordable Care Act
(which both require disclosure and simplification of information to consumers),
as well as an initiative called MyData which helps citizens use their digitally
stored personal data to obtain more appropriate services to their specific needs
(Lunn 2014). Sunstein (2011) has published detailed guidelines of how behav-
ioural economics and evidence-based policy making are to be used in making
government more effective.
Many of these initiatives aimed to adapt existing policies taking into
account the idea of “framing” of information: for example, the nutritional
recommendations’ “food pyramid” was revised into a “food plate”. According
to Lunn (2014), one of the debates in which nudge has featured heavily is
New York City’s proposal to ban large sizes of soft drinks. The example pre-
sented earlier of energy labelling for appliances in the U.S. with framing in
terms of costs is also employed for fuel efficiency labels on vehicles (presented
in detail in section 6.3.1).
Cass Sunstein resigned in 2012 from OIRA. He subsequently published
a book on the challenges of simplifying government and making it more effec-
tive using insights from behavioural economics (Sunstein 2013). The White
House’s efforts to promote the use of nudges as a new tool for government
has provoked significant controversy, which is partly due to the adversarial
political climate in federal politics in the USA, see (Hansen and Jespersen
2013). Perhaps “nudge” has been an easy target, since it has been often misrep-
resented as an effort to extend the reach of government wider and deeper into
the lives of Americans. On the other hand, proponents have countered such
criticism by presenting behavioural insights as offering a tool for making gov-
ernment more cost effective and reducing unnecessary and costly bureaucracy.
Nonetheless, in summer 2013, the White House appointed a 4–5 person
“behavioural insights” team at the Office of Science and Technology Policy
(OSTP). The team aims to enhance federal agencies’ capacity to apply behav-
ioural insights, create and provide resources for the agencies, and convene
a “multi-agency community of practice” to identify and share promising
practices and common challenges (OSTP 2013). This new federal team is
inspired in part by the Behavioural Insights Team in the UK (see below).
Nudging – A tool for sustainable behaviour?
5.2 UK
In the UK, nudge was firmly institutionalised when establishing the Behavioural
Insights Team (UK BIT) at the UK Cabinet Office in 2010. This team was tasked
to work as a kind of in-house consultancy developing interventions collabo-
ratively with government departments, agencies and the private sector. It
has contributed to policy development especially in public health, consumer
policy, sustainability and enhanced compliance with tax and fine collection
(Lunn 2014).
In February 2014, the team was ‘spun out’ of government and set up as
a social purpose company working in co-operation with Nesta, a trust-based
charity (formerly government-funded) that promotes innovation. A third of
the shares will be owned by the staff, a third by Nesta and a third by the gov-
ernment. The UK BIT team still works primarily for the Cabinet Office and
the health and energy departments, but also for other clients including foreign
governments, municipalities, NGOs, private sector partners and international
organisations. The use of behavioural insights is voluntary for UK government
departments, and there are some concerns that the influence of the UK BIT in
policy design might decline since they were divested from the Cabinet Office
(Johnston 2014).
The UK BIT team has a staff of 16 people, with backgrounds in academia
(behavioural sciences and experimental methodology), policy making and
marketing. It is responsible for developing and testing interventions that sup-
port better choices, advancing and applying behavioural science in public
policy and promoting evidence-based policy and evaluation.
There are several examples of improved policy implementation based on
the nudge principles in the UK (Lunn 2014). These include improved fine
collection by making it more convenient to pay fines and sending more per-
sonalised reminders. The UK BIT also organised trials that led to improved
take-up of insulation measures, again by increasing the convenience of par-
ticipation in the insulation programme. As concerns sustainable consumption,
the UK BIT has been particularly involved in promoting sustainable behaviour
change in residential energy investments and habitual energy behaviour (UK
Cabinet Office 2011). Examples of projects in this field include input into the
planning of the Green New Deal, a scheme for financing energy renovations,
improvements to the Energy Performance Certificate design, trials with energy
consumption feedback formats, as well as dedicated trials to improve loft
insulation takeup by reducing hassle for homeowners to clear out loft, as well
as a peer-to-peer marketing project to spread interest in loft cavity insulation
(UK Cabinet Office 2011).
The work of the UK BIT team is based on a range of behavioural science
findings utilised in designing and testing better policy interventions (Harford
2014; Service et al. 2014). In consumption-relevant domains, the interven-
tions are fairly similar to earlier interventions in the UK that used sophisticated
social marketing approach, see e.g. (Futerra 2007). Much of that work have
Nudging – A tool for sustainable behaviour?
been systematised in the report MINDSPACE,9 which outlines nine principles
for behaviour change promotion by government (Institute for Government
and Office; 2011). The key point is the systematic involvement of behavioural
experts in policy design and the testing of alternative solutions for delivering
the policy with the use of randomised control trials. The focus of the UK BIT
team has been very much on policy implementation, e.g. improving the collec-
tion rate of fines and taxes, making it easier for the unemployed to apply for
a new job, or increasing the rate of people enrolled as organ donors (Service
et al. 2014).
5.3 EU
Behavioural insights have been applied in EU consumer policy since 2009 (van
Bavel et al. 2013). The Consumer Rights Directive was the first EU legal text
to recognise the power of default options by limiting the use of pre-checked
boxes in standard contracts (for example, for the inclusion of extra services
in hotel or travel packages). Behavioural insights have also been cited in con-
nection with the high-profile competition case against Microsoft, as a result
of which consumers must be allowed an active choice of which browser to use
with Microsoft Windows (van Bavel et al. 2013; Lunn 2014). DG SANCO
has continued to be the most active administration in using and promoting
the use of behavioural insights.
In 2010, the DG SANCO ran the first large behavioural study to find out
how consumers search for information and choose between retail investment
products (Coggi 2012). Through a series of online and face-to-face experiments,
DG SANCO found that consumers struggle to make good investment choices;
only 2% of the subjects made all five of the tested investment choices optimally.
The results of the study suggested that standardisation and simpler product
information are needed. The Commission used the results of the study to
review the legislation on packaged retail investment products.
Since other directorates were also interested, DG SANCO established
a Frame-work Contract for the Provision of Behavioural Studies, open to
all Commission services and requested scientific assistance from the Joint
Research Centre. This collaboration has led to numerous studies and experi-
ments on e.g. retail investment funds, travel packages, tobacco labelling, CO2
labelling for cars and energy labelling (van Bavel et al. 2013; Lunn 2014).
In EU policy making, the use of behavioural insights has been promoted
via information provision and advice to various directorates of the European
9 MINDSPACE is a mnemonic for these principles, which are Messenger (we are heavily influenced by
who communicates information), Incentives (responses to incentives are shaped by predictable mental
shortcuts such as loss aversion), Norms (we are strongly influenced by what others do), Defaults (we “go
with the flow” of pre-set options), Salience (our attention is drawn to what is novel and seems relevant
to us), Priming (our acts are often influenced by sub-conscious cues), Affect (our emotional associations
can powerfully shape our actions), Commitments (we seek to be consistent with our public promises),
and Ego (we act in ways that make us feel better about ourselves).
Nudging – A tool for sustainable behaviour?
Commission. For example, JRC report by van Bavel et al. (2013) offers advice
on how to apply behavioural science in policy making in the European
Commission (described in section 7.1).
Some academics have argued that behavioural insights should be included
in a more formal way in European regulatory developement, rather than the
current voluntary procedure, for example by introducing a mandatory behav-
ioural test into its regulatory impact assessment system (Alemanno 2012).
This has not yet been implemented in the European Commission. However,
more collaboration among scientists and policy makers across Europe is to
be expected in the future. The Euro-science Open Forum (European Science
Foundation) is hosting its conference in June 21–26. One of the satellite events
aims to establish a European Nudge Network, i.e., platform for accelerating
information dissemination and collaboration on the use of nudge across Europe.
5.4 Denmark
Instead of establishing a governmental unit, Denmark has an active organisa-
tion outside the government supporting the use of nudges in policy making.
iNudgeYou10 is a non-profit organisation with the explicit mission to test and
facilitate the use of behaviour changing tools in practice in various spheres of
life (Lunn 2014).
The organisation grew out of an initiative by the Initiative for Science,
Society & Policy (ISSP) at Roskilde University and the University of Southern
Denmark. One example of the iNudgeYou team’s contributions is a project
for the City of Copenhagen to reduce littering. Experiments showed a 46%
reduction in street-litter by applying green footprints on the streets leading
to waste bins, which served to make litter more salient and to activate social
norms. iNugeYou also initiated and helped draft a suggestion for prompted
choice for organ donation to be put before Danish parliament. They have
adviced several Danish authorities, including The Danish Business Authority,
The Danish Competition and Consumer Authority, Danish Environmental
Protection Agency, and The Danish Energy Agency.
INudgeYou has also set up the ‘Danish Nudging Network’ (DNN) which
aims to establish a network of researchers, practitioners, stakeholders and
policy makers interested in the use of behavioural science, and also organises
workshops and courses on promoting the use of behavioural science in policy
making (INudgeYou 2014).
The organisations runs a successful blog where latest news on nudging are
shared and the results of projects run by INudgeYou are presented.
Nudging – A tool for sustainable behaviour?
5.5 Norway
Similarly to Denmark, Norway has an independent organisation promoting
and supporting the use of nudges, GreeNudge11. GreeNudge has an explicit
focus on sustainability and aims to initiate, fund and promote research into
behavioural change as a means to mitigate climate change. Examples of pro-
jects include investigation of the rebound effect of heat pumps, the reduction
of food waste in cafeterias, and an experiment to promote the sales of energy
saving appliances by adding information about total life cycle costs to the
energy label (Kallbekken et al. 2013).
GreeNudge (2013) has produced a report on the potential for nudging in
Norway’s climate policy. It presents nudging as an attractive policy instrument
for climate policy because it does not entail coercion and thus reduces potential
resistance. Compared to other climate policy instruments, it entails low risk,
especially since measures are tested before implementation. Behavioural inter-
ventions are argued to be relatively quick and simple to implement and cost
effective. As an example, the food waste reduction project delivered savings of
25 000 NOK per ton of CO2 mitigated. The report also emphasises the poten-
tial to combine climate policy measures with health benefits.
GreenNudge has also co-operated with a climate programme among the
13 largest towns in Norway (Fremtidens Byer). In spring 2014, the municipal
council of Lillehammer decided to establish a dedicated committee on nudge,
focusing on climate change mitigation, cost effective government and health
promotion. The committee will first study the potential for nudges, design
measures and seek project funding. The project will be implemented together
with Høgskolen i Lillehammer, which is starting the first Master’s programme
in applied environmental psychology in the Nordic countries (GreeNudge 2014).
Nudging – A tool for sustainable behaviour?
6 Nudge in various consumption-
relevant domains
In the previous sections, many examples of nudging came from financial or
health domains. The question remains whether nudging can help change
behaviour in the consumption domains with largest environmental impacts.
Governments are typically cautious with applying coercive policy measures
to the realm of consumption and the daily lives of consumers, as such policies
might be perceived of as encroaching on consumer sovereignty. On the other
hand, any policy influences behaviour, directly or indirectly.
Nudge might be a promising tool for advancing sustainable consumption
because nudge tools do not restrict consumer choice (Sunstein 2014a). So, in
which consumptions domains has nudge proven to be most efficient and effec-
tive? And what are the critical factors of success?
The three most environmentally relevant areas of consumption, which
together sum up to 75–80% of the life cycle environmental impacts in industri-
alised countries are housing (especially heating systems), transport (especially
car use and air travel) and food and drink (especially meat and dairy) (EEA
2013). These areas are also the ones where nudge researchers and practitioners
see the largest potential (Stordalen and Kallbekken 2014). Below nudge exam-
ples and activities in energy, food and mobility domains are analysed.
6.1 Energy use in the home
In Sweden, as in many countries, buildings account for about 40% of energy
use. However, the share of CO2 emissions is lower in Sweden because less
fossil fuels are used (Swedish Energy Agency 2012). Nonetheless, the reduc-
tion of energy use in households is an important target. Decades of evidence
suggest that people consistently under-invest in energy efficiency, even from
a private economic viewpoint – a phenomenon which is often referred to
as the “energy efficiency gap”, e.g. (Persson et al. 2009). This suggests that
residential energy use could be a very appropriate target for nudges since
behaviour is not economically rational.
Residential energy efficiency is influenced by two types of behaviour.
Much of our energy usage in households is routine behaviour, which is not
the subject of conscious choices. Energy use is a “side-effect” of other things,
like cooking, cleaning or having a comfortable home. Such routines have their
own momentum, and just getting someone to do something differently once
is not enough; policy makers need to change the pattern (hence, nudges need
to be permanently in place). Energy efficiency investments are more conscious
and made more rarely; thus, people look for and process more information
in order to make the decision. If interventions are successful in targeting the
efficiency/ investment behaviour, the effects of this behaviour are durable since
Nudging – A tool for sustainable behaviour?
investments are usually less easy to reverse, e.g. additional insulation will
probably remain in the house even after it is sold.
Nudge-type interventions are traditional in the field of energy use in the
home, even though they have been only recently labelled “nudge”. For exam-
ple, feedback on electricity bills providing social comparison information (i.e.,
comparing the recipient’s energy use to that of other similar households) was
tested in Helsinki already in 1989–1992 and was found to reduce electricity
consumption by about 1–1.5% (Arvola et al. 1993) and has been used ever
since. Smart meters and modern ICTs have been able to leverage this effect to
an even greater extent, as will be shown in the following section.
6.1.1 Evidence for the effectiveness and efficiency
Several nudge-based mechanisms have been used over the years (some even
since several decades) to promote residential energy efficiency (Stern 1992).
Table 4 displays the types of intervention most commonly used according to
mechanism type and the available evidence concerning its effectiveness.
Table 4 Nudge mechanisms used to influence residential energy consumption
Nudge mechanisms used
Applications to residential
energy efficiency
Evidence of effectiveness
Simplification and framing of
Feedback on energy consump-
tion: Informative energy bills,
metering and displays
Extensive research on all
scales: tailored and small-
scale interventions render
1–20% savings, large field
trials about 2%
Energy labelling of appliances
and buildings
Experience on a large scale,
but limited evaluation of
Changes to the physical
Design for sustainable behav-
iour, Design with intent (of
homes and appliances)
Small scale trials, little
evidence of the size of
the effects
Standard in some environ-
ments such as hotels (key
card removal turns of lights)
Prompts as reminders of
appropriate behaviour
Small scale trials, evidence
of effectiveness as part of
a package of interventions
Changes to the default option Opt-out green electricity offers 95–99% of customers stay
with the “green electricity
Opt-out from smart grid trial
(technology installed to
control consumption)
Large effects (20%) in one
survey study
Use of descriptive social
Social comparison billing
Large effects in small scale
trials (average 11%), smaller
effects in large field trials
(e.g. 2% savings)
Nudging – A tool for sustainable behaviour?
More details are provided below on each application. Feedback on energy
consumption, i.e., informative billing, metering and displays have been
popular energy policy instruments. For decades, there have been attempts to
improve electricity bills, which have traditionally been very counterintuitive.
Before the introduction of automatic meter reading, meters were often read
only once a year and e.g. quarterly bills were based on estimates. Because of
this, it was difficult for households to know how much electricity they were
consuming (Fischer 2008). Informative billing has been a way to simplify
electricity bills and make the information provided more actionable. Since the
introduction of automatic meter reading, also smart meters and displays are
being designed to simplify and frame electricity consumption information in
the best possible way. In Sweden, all households have electricity meters that
are read at least once a month and billed at least four times a year.
Fischer’s (2008) review of previous studies found evidence for the effec-
tiveness of feedback with savings ranging from 1–20%, and with some studies
showing no savings. In a closer analysis of what differentiates the “best case”
studies, Fischer concluded that feedback is most effective when it is frequent,
involves interaction and choice for households, includes a breakdown of
consumption by appliances, is given over a long period, and is presented in
an understandable and appealing way. Delmas et al. (2013) have conducted
a meta-analysis of various kinds of intervention studies and experiments. They
found that feedback rendered average energy savings of about 7%. However,
results obtained in small-scale field interventions are not necessarily replicated
when the intervention is rolled out on a larger scale. For example, Darby
(2012) has pointed out that many early feedback and smart metering studies
used selected samples: wider interventions and rollouts involving hundreds or
thousands of households render lower savings of about 2%.
There is also some evidence on the efficiency, i.e., cost effectiveness, of
feedback as a tool to influence residential energy consumption. This has been
produced in the context of social comparison feedback, and thus is discussed
below after that heading.
Energy labelling is a policy-level application of the principles of simpli-
fication and framing of information, and also of providing the information
near to where the choice is made. Labelling might not strictly be considered
a “nudge”, since it does not merely rely on nudge-type “automatic” fast
thinking, but could also include cognitively processed information (Ölander
and Thøgersen 2014). Informative energy labelling (rating of appliances
according to energy classes) is mandatory in the EU for all the most common
types of electrical appliances. Energy labelling in the form of the Energy
Performance Certificate is today also applied to buildings. Since 2009, all
Swedish buildings must bear an Energy Declaration of Buildings with infor-
mation on the energy performance, a reference value for comparison and pro-
posals for appropriate energy efficiency measures. However, there has been
some discussion on the design of the declaration (Fuglseth 2009), which some
consider is not as salient and well-framed as in other countries.
Nudging – A tool for sustainable behaviour?
The EU Energy Label is generally considered a great success. For example,
an experiment conducted in the USA (Newell and Siikamäki 2013) found the
EU Energy Label to be the most effective among several types of information,
generating the greatest willingness to pay for energy efficiency in a heating
appliance. The success of the EU Energy Label lead to the situation when in
many product categories the majority of products have reached the A-level
efficiency. The scheme has recently been upgraded to include up to A+++ cat-
egories to incorporate the most efficient products. Heinzle and Wüstenhagen
(2012) and Ölander and Thøgersen (2014) found that as a result of this revi-
sion of the label, consumers are less sensitive to the most efficient categories,
and tend to perceive all the A categories as fairly similar.
There is evidence that the inclusion of life-cycle cost data alongside or
as part of the energy label could further improve the effectiveness of energy
labelling. For example, Kallbekken et al. (2013) tested the addition of lifetime
energy use data on two product categories, fridge-freezers and tumble driers,
accompanied by the training of sales staff. For fridge-freezers, the authors find
no significant effects. For tumble driers, the combined life cycle cost and staff
training reduced the average energy use of tumble driers sold by 4.9%.
Design for sustainable behaviour aims to change the physical environment
to support more sustainable behavior. When applied to residential energy
consumption, the aim is to change the users’ physical environment so that it
supports energy conserving behaviours and discourages energy wasting ones.
For example, a refrigerator can be designed so that it is more difficult to keep
the door open when stocking food in it (e.g. an alarm), or so that it is easier
to locate food and keep it at the correct temperature (Bharma et al. 2011).
Lockton et al. (2009) and Schmaltz and Boks (2011) have demonstrated how
design for sustainable behaviour can be applied to reduce energy consumption
in lighting. Even though there is limited experimental evidence of the effec-
tiveness of this approach, logic and analogies suggest that this is an effective,
but expensive intervention, unless it is integrated smoothly into new product
development and eco-design principles. More generally, human factors and
usability design are well-established design principles which draw on behav-
ioural science, similarly to nudge (Norman 1988).
Prompts are low-cost changes to the physical environment that aim to
influence error-prone repetitive behaviour, such as stickers reminding the
building user to turn the lights off. Prompts are “memory aids” that are pre-
sented in close proximity to where the behaviour occurs and should ideally
focus on reminding people what the positive behaviour is (McKenzie-Mohr
and Schultz 2014). Prompts are widely used in local energy saving campaigns.
Practitioners and the literature consider prompts to be effective in connec-
tion with a broader package of measures promoting energy conservation.
However, the effect easily wears off, and they can be perceived of as annoying
by some consumers (Backhaus and Heiskanen 2009).
Nudging – A tool for sustainable behaviour?
Changes to the default option are more recent, and until now only experi-
mentally used tools in residential energy efficiency. The main applications are
“opt-out” rather than “opt-in” contracts. In an opt-out contract, consumers
are given the environmentally friendly choice as a default, but are allowed the
option “opt-out” if they do not want it. This is in contrast with an “opt-in”
contract or choice. For example, in order to choose “green” (renewables-based)
electricity, consumers usually have to make an explicit effort to switch to an
alternative electricity provider. An “opt-out” model would offer the consum-
ers the “green” choice as the default, and they would actively have to choose
“standard” electricity if they want to.
Several studies report that consumers are much more likely to select
“green” electricity if this is offered as the default option. For example, Pichert
and Katsikopoulos (2008) report of two “natural” experiments in Germany
in which 95–99% of the consumers stayed with the “green” electricity default
rather than switching to a “grey” cheaper but fossil-based electricity supply.
Recently, there has also been research on other aspects of residential energy
use. Ölander and Thøgersen (2014) report on a study that examined consum-
ers’ willingness to participate in a “smart grid” trial where their household’s
consumption could be automatically reduced at peak electricity demand
periods. They experimented with two ways of offering this to consumers:
one group (N=345) was offered the choice to “opt-in” to the trial (choose
the option to participate), the other (N=332) was offered the choice to “opt-
out”(choose the option to not to participate). The opt-in design rendered
a 60% participation rate, whereas the opt-out option rendered a participation
rate of almost 80%.
Social comparison feedback builds on the mechanisms of descriptive
social norms, i.e., the fact that people (mostly unconsciously) tend to follow
the example of other people surrounding them. This mechanism has been
tested widely in electricity billing. Comparative feedback on energy use offers
consumers factual information comparing their own consumption to that of
other similar households. Modern technology, such as smart meters and dis-
plays, offers cost effective opportunities to provide such feedback frequently
and accompanied by forceful visual effects, such as smiley faces for those con-
suming less than average (Thaler and Sunstein 2008). There is a great deal of
research on the effectiveness of this mechanism. For example, a meta-analy-
sis by Delmas et al. (2013) found an average effect size of 11.5% savings for
social comparative feedback, although they note that most of the published
studies refer to smaller scale trials than for some other interventions. Some
larger trials have recently been conducted. Allcott and Mullainathan (2010)
evaluated a series of programs run by a company called Opower, which sent
Home Energy Report letters to residential customers comparing their electric-
ity use to that of their neighbours, with treatment and control groups total-
ling 600,000 households in the USA. The comparative feedback was found
to reduce electricity consumption by 2% on average. Early research on social
comparison feedback suggested that some consumers who initially consume
Nudging – A tool for sustainable behaviour?
much less than average might increase their consumption when they are
informed of how much the average consumer consumes, e.g. (Fischer 2008),
which makes sense since social comparison feedback aims to “show people
what is normal”. Some specific measures have been developed to counter this,
such as smiley faces to show what is positive and what negative behaviour
is. In a comprehensive evaluation of two large-scale trials of social feedback,
Ayres et al. (2013) found that the least-consuming households did not increase
their consumption when they received the smiley face symbols and informa-
tion of how much not only average, but also “efficient” neighbours consume.
However, the social comparison feedback was most effective in the households
with the highest energy consumption (Ayres et al. 2013). There is also some
evidence on the efficiency of social comparison feedback from a cost-benefit
perspective. Ayres et al. (2012) estimated that the Opower reports cost less
than 5 cents per kWh saved, which is on par to the cost effectiveness of other
types of energy saving programmes, and could be further reduced via electronic
delivery of reports. Alcott and Mullanaithan (2010) report even lower costs
from the same reports in another region: 2,5 cents per kWh saved. Moreover
Ayers et al. (2012) have calculated that the effects of the Opower reports are
equal to those of raising electricity taxes by 3–7%, which is likely to be less
politically feasible than the reports.
6.1.2 Critical success factors of nudging strategies
The critical success factors for nudging strategies in influencing residential
energy efficiency behaviours are similar to overall critical success factors for
policies in this area (Stern 1999; Dahlbom et al. 2009; Heiskanen et al. 2009):
Nudging should be part of a broader policy package combining several instru-
ments. It should be based on a careful analysis of the kind of behaviours one
wants to change and on the factors influencing them. By developing a better
understanding of why people use energy wastefully or do not follow advice
about energy saving or respond to the financial incentive to save, improvement
can be made to current market stimuli and energy policy measures. For exam-
ple, sometimes the barriers to participation in an energy saving programme can
be quite high and may require significant support. For instance, some people
might not sign up for a home energy renovation even if it is offered for free
because of the inconvenience; they might be helped to do so if the municipality
offers to move their furniture, see (Backhaus 2009; Lunn 2014).
Moreover, the success of nudge – like any other instrument – will depend
on the context and on the type of behaviour targeted. Nudge-based policies
should be based on research into energy end-user behaviour and its context.
There is a great deal of such research already available in Sweden, see (Alm
et al. 2012), and behavioural scientists are likely be able to suggest a range of
improvements or interventions for further development and testing. Moreover,
Sweden has a large number of researchers and higher education institutions
that could participate in testing, evaluating and improving interventions.
Nudging – A tool for sustainable behaviour?
Nudges should be targeted at types of behaviours which they are capable of
influencing. Daily patterns of energy consumption are habitual and “auto-
matic”, hence very appropriate for being influenced by nudges. There are also
more rarely made investment decisions, like the choice of a heating system or
the decision concerning what kinds of windows to install, which are likely to
be appropriate since they are complex decisions involving a large amount of
detail, and research indicates that consumers are quite susceptible to external
influences like the recommendations of installers (Nair et al. 2012). It is also
important to recognise that there are broader sustainable consumption issues
related to residential energy use where the nudge approach might not offer so
many benefits. This is because energy efficiency improvements are countered
by a decrease in household size resulting in fewer occupants sharing the same
space and an increase in the number of electrical appliances (Swedish Energy
Agency 2012). Such issues of consumption growth and socio-demographic
change are not likely to be amenable to nudge-based interventions, at least in
their current form.
6.1.3 Lessons learned for devising more successful policies
As stated, many of the basic “nudge” tools have been used for decades in
energy efficiency policy (Stern 1992). Energy use in the household is an area
where behaviour is obviously not economically rational (people could save
money if they saved energy, but they do not). It is also an area where psychol-
ogists and sociologists have been involved in developing policy advice since
the energy crises.
One of the important contributions of behavioural economics to energy
efficiency policy is to counteract the economics-based reasoning, which argues
that there cannot be an “energy efficiency gap” since people always behave
rationally (Geller and Attali 2005; Gillingham and Palmer 2014). Nudge sup-
ports the idea that we do need energy efficiency policy. Secondly, even though
nudge-based ideas are applied in energy efficiency policy, they are often applied
unsystematically and sporadically. Electricity bills are still incomprehensible
(though slightly less so), even though everyone knows about information over-
load and the importance of information framing. “Smart” meters and displays
are not designed from the user perspective to take into account framing, simplifi-
cation of information, defaults or any of the other nudge principles. Appliances
are still difficult to use correctly and they are designed so that they allow
inappropriate user behaviour. Buildings are even more difficult to use appro-
priately, and are becoming more so due to the continuous integration of new
technologies. Hence, the lesson from the literature would be to apply “nudge”
and human factors design throughout the built environment, in energy-using
appliances and every aspect of the information environment (contracts, adver-
tising, invoices, online advice, television programmes, etc.) which influences
residential energy use.
Nudging – A tool for sustainable behaviour?
Resources, however, are limited. Even though “nudge” is effective and even
efficient in many cases, it requires a great deal of tailored and customised
attention. Hence, it would be best not to apply “nudge” as a separate policy
area, but as an integrating and cross-cutting design element in at least the fol-
lowing policies:
The Ecodesign Directive and building codes: policy makers could work
to include “green defaults” and require that appliances are designed to
enable and trigger sustainable behaviour. Examples could include “low-
energy settings” and “automatic sleep mode” for TVs as the default set-
ting (these are currently provided as options at least for LED TVs if the
user can find them). If they were offered as defaults, users who do not
want these features can then actively change them. Further benefits could
be gained by considering the efficiency of entire systems rather than indi-
vidual products.12
Support schemes for residential energy-efficiency investments: these also
could include “green defaults” and require that systems are designed
for sustainable behaviour. For example, the most energy efficient option
(window, heat pump) could be the default for receiving a subsidy (other
solutions could receive subsidies with special justification) and only appli-
ances and solutions that are well-designed to support appropriate user
behaviour could qualify for subsidies. Advice material related to the
scheme could be designed with human factors in mind.
Labelling of appliances and buildings could be improved through
better design, as described in some of the examples presented above.
Additionally, building contractors, renovators and owners could be
required to remind users of appropriate behaviours in the context where
that behaviour occurs (e.g. with stickers). There is already quite a lot of
usability and user research on building systems, which could be employed
to support energy conservation, e.g. (Karjalainen 2007).
Improvement of “smart” metering and billing practices could include e.g.
“green defaults” for demand response in peak consumption periods (if
this is legal and considered relevant by the authorities). More practically
and immediately, such improvements could also include better design
of metering and billing services to incorporate all the best lessons from
international examples. Many such measures are already in use, such as
consumption feedback obtained via automatic meter reading of electric-
ity consumption. The notion of nudges could however improve the kind
of feedback given on people’s electricity bills or on meter displays, which
could be more effective than it is today if they were designed with a more
sophisticated understanding of behaviour and through systematic testing
of alternative designs.
12 See for example
Nudging – A tool for sustainable behaviour?
Automatic meter reading offers the possibility to develop tailored energy
saving advice, contract models and energy efficiency packages adapted to
the users’ particular preferences, appliance stock and behaviour patterns.
In the UK, the possibility to use digital personal energy use data in this
way is being explored (Lunn 2014).
Descriptive social norms could be widely utilised, if there is political will,
to change the kind of social example presented to people in the media
and in their social surroundings. We are currently surrounded by social
examples of wasteful energy use – for example, in American television
shows or in home decoration and renovation programmes. This shows
people that wasteful use of energy is the norm. It is, however, not clear
how policy makers could change this situation.
Policy makers should not have unrealistic expectations toward the added
value of nudge-based interventions in residential energy efficiency, since
behavioural science is already widely integrated in several energy efficiency
policy fields, such as energy labelling, even though the current situation can
always be improved. There might be new policy areas where this type of
advice has not yet been recognised and where it would be administratively
easier to integrate. For example, a specific area of current concern is the
actual, measured energy usage of low-energy buildings, which often exceeds
that of design specifications due to user and operator behaviour (Karlsson
et al. 2007; Heiskanen et al. forthcoming). Instead of providing users and
operators with more information, such buildings could be designed to “auto-
matically” trigger the appropriate kinds of behaviours. Moreover, information
and training of users and staff could make use of the ideas of simplified infor-
mation, framing and social comparison feedback from the nudge paradigm.
6.2 Food
Food production and consumption have major impacts on the environment.
Agriculture is responsible for 13% of all greenhouse gas emissions in Sweden
(Naturvårdsverket 2014), and overall food consumption represents about
25% of the climate impact of an average Swedish consumer (Röös 2012).
Other potential negative impacts of food production and consumption are
biodiversity loss, eutrophication, soil degradation and the pollution of land,
air and water.
Increasingly, the impact of food consumption in Sweden happens abroad
(Naturvårdsverket 2014). Due to increasing imports, production-oriented
measures to reduce agricultural impacts are therefore becoming less effective.
This increases the relevance of consumption-oriented policy-making.
Food consumption is to a large degree a habitualised and in many cases
relatively unreflective process, e.g. (Gronow and Warde 2001), which makes
it prone to nudging. Restaurants and other out-of-home consumption places
(e.g. school canteens, workplaces) offer an environment that can be influenced
Nudging – A tool for sustainable behaviour?
by policy makers. Even food consumption in private homes – which is hard to
reach directly for a nudge intervention – lends itself to nudging though indirect
means (i.e. the act of grocery shopping in the store).
6.2.1 Evidence for the effectiveness and efficiency
Nudging has been applied in the food domain primarily in attempts to cope
with the increasingly problematic obesity epidemic in many Western countries,
notably in the USA. To a lesser extent, nudging has been applied to promote
environmental causes in food consumption, for example to reduce meat con-
sumption (and thereby climate change) and food waste.
Table 5 Nudge mechanisms used to influence food consumption
Nudge mechanisms used Applications to food
Evidence of effectiveness
Simplification and framing of
Provide simplified information
and signifiers
Small-scale studies in con-
trolled environments indicate
large impact; no large scale
studies available; impact
seems to vary for different
segments of society
Changes to the physical
Change visibility and
Strong evidence in controlled
environments (i.e. canteens;
Influence size Experiments with portion size
and package size suggest
strong impact
Changes to the default option Positioning of product choice Wide use in retailing suggests
large impact; few studies
available for pro-sustainable
Use of social norms Provide information about
others’ behaviour and ideal-
type behaviour
Studies suggest effectiveness,
particularly when behaviour is
publically visible and in cases
of uncertainty about appropri-
ate behaviour
Provide simplified information and signifiers: Simplified information tailored
to specific choice situations increases the likelihood of influencing individual
consumers. Signifiers refer to information that is added to a context in order
to make certain information more salient. Kalnikaitė et al. (2013) found that
grocery shoppers base their choices in supermarkets on a very limited number
of factors, and thus the salience of various factors matters. Most often these
factors are price (for 46% of respondents) and health (36%), but they can be
modified depending on the choice context. It is thus obvious that simplified
information is necessary to influence grocery shopping choices. Governments
have long been aware of this fact and engaged in legislation to simplify infor-
mation. Nutritional information requirements (including their design) were
introduced by most governments in the late 20th century. More recently, regu-
lation was also passed regarding marketing claims considered to mislead con-
sumers, such as unproven health claims. Both fields are now regulated at the
European level.
Nudging – A tool for sustainable behaviour?
A more radical example of simplified information provision in food con-
sumption is the much discussed ‘street light system’, indicating good choices
(green), neutral choices (yellow) and bad choices (red). This regulation has
been tested in several countries (e.g. Germany) and various contexts, but no
government has formally introduced it as an obligatory requirement.
Oullier, et al. (2010) report on a range of examples of nudging to promote
healthy eating. In one experiment, crisp consumption was reduced by 50% by
adding red-coloured crisps in regular intervals in a tube of crisps (i.e. ‘Pringles’
packaging). As explained by Oullier, et al. (2010, p. 44) “[u]sing these visual
markers draws the attention of the eater, gives them points of reference for
their own consumption and causes them to interrupt that consumption”.
Campos et al. (2011) reviewed studies on nutrition labels on pre-packaged
foods and found that these labels enjoyed high trust among consumers. They
also found that those consumers who use these labels have healthier diets.
However, only some consumer segments (individuals with health conditions
and special diets) show high user rates of such labels, while other consumer
segments (children, adolescents, older adults) show low use of nutrition labels.
Campos et al. (2011) conclude that to be effective with all consumer groups,
labelling regulations need to take the entire package into account. Otherwise,
information provided on the rest of the package can outcompete nutrition
labels for consumer attention.
An example of the effectiveness of signifiers comes from the Swedish
burger chain Max. They introduced carbon labels on all of their burgers and
witnessed a 16% increase in sales of those burgers with a lower than average
carbon footprint (van Gilder Cooke 2012).
Another example of the impact of menu design comes from Fox et al. (2005).
They found that the way the menu was designed impacted the amount of
unhealthy food chosen. By segregating healthy menu options (fruits, vegeta-
bles) but clustering unhealthy menu options (cookies and candies) the relative
purchase of healthy options was increased.
Kalnikaitė et al. (Kalnikaitė et al. 2013) used a simplified information
system to indicate good, neutral and bad product choices to consumers. The
two information parameters were 1) food mileage, and 2) organic or non-
organic production methods. The study was performed in a supermarket,
with a trolley equipped with a clip-on lambent device. This device consisted
of a line of LED lights, which indicated both the food mileage (the number of
LEDs lid indicated distance) and production method (changed colour to indi-
cate organic or non-organic production). The device further featured a signi-
fier for good or bad behaviour in relation to other consumers. A little display
showing a happy face, an indifferent face and a sad face was visible to the
consumers, which indicated the comparison of the total content of the shop-
ping trolley compared to a social norm (i.e. an average shopper). The study
showed that 72% of chosen products had lower mean food mileages than
when no such device was present. They also found that this effect was strong-
est where information on food mileage was small or not present at all on the
Nudging – A tool for sustainable behaviour?
product package. At the same time, no impact was observed for the organic/
non-organic parameter, which they explained with the prominent presence
of the ‘organic’ label on food packaging when the product is of organic agri-
culture. This supports the idea that salience plays a great role in individual
Changed accessibility and visibility: Many studies have been conducted
on the possibility to influence individuals to chose healthier food in restau-
rants and canteens. Brian Wansink from Cornell University, NY, has con-
ducted numerous experiments on nudging in this context, e.g. (Wansink and
Van Ittersum 2003; Wansink 2004; Wansink and Cheney 2005; Wansink and
Kim 2005; Wansink and Chandon 2006; Wansink 2010). The overall picture
these studies draw of the potential of nudging in ‘out-of-house catering’ con-
texts is that the impact of visibility, presentation and experience of food has
significant impact on the type and amount of food consumed. Easy access
to unhealthy food, for example, significantly increases consumption of such
food. Even the visibility and smell of unhealthy food impact consumption
levels. Wansink (2004) reports on studies showing that an ice cream cooler
without a lid resulted in higher ice cream consumption. The availability of
a milk dispenser or a water pitcher close to the dining area also resulted in
higher consumption of milk and water. Finally, Wansink could find an effect
of plate and glass design on food consumption. Where bowls and glasses were
wider but shorter total food and drink consumption increased significantly
(Wansink, 2004). In one experiment with teenagers at weight-loss camps,
offering short, wide glasses to them increased their juice and soda consump-
tion by 88% compared to tall, narrow glasses (Wansink and Van Ittersum
2003). Some studies even point to relatively unrelated visual cues having an
effect on food choices. Johnson et al. (2012) report on studies conducted
in high school cafeterias, where the presence of bananas and green beans
decreased sales of ice cream, while the presence of sugary side dishes (e.g. fruit
cocktail, applesauce) increased sales of cake and chips.
Influence size: Not only the appearance of food plays a significant role in
how much is consumed. Even more so, it seems that size matters. Wansink
and colleagues conducted numerous studies on the impact of portion, plate
and spoon size on the amount of food consumed. For example, when indi-
viduals were given a ca. 680 g bowl (24 ounces), they served themselves 31%
more of ice cream on average compared to when they were given a 450 g
bowl (16 ounces). In another experiment in which spoon size was influenced,
patients increased their dosage of cough medicine by 22%. Wansink (2004),
who reports on all these experiments, relates this to the effect that size has
on humans’ perception of what is a normal size. Similar findings are reported
about package size for snacks: when they are doubled, consumption increased
by 18–25% for meals and 30–45% for snacks (Wansink 2004).
Other studies also show that reduced plate size (in all-you-can-eat environ-
ments) (Freedman and Brochado 2010) and reduced portion size (Rolls et al.
2002) both reduce total calory intake and food waste. Focusing on the effect
Nudging – A tool for sustainable behaviour?
of size on food waste, Kallbekken and Sælen (2012) conducted a study among
hotel guests in Norway. They reduced the plate diameter from 24 to 21 cm
at restaurant buffets in 7 hotels and found that, on average, food waste was
reduced by almost 20%.
Not only the size of one product or portion matters, but also the size of
the entire offering. If more choices are offered to an individual, the total con-
sumption is likely to increase. For example where consumers were offered
three different flavors of yogurt (compared to only one option) the average
consumption of yoghurt increased by 23%. Where individuals were offered
M&Ms with ten different colours (compared to seven) consumption increased
by 43% (Wansink 2004).
Positioning of product choice: People tend not to observe their environment
in its entirety. Usually, attention is restricted to a small section of the total
context, and clear preferences for certain visual areas (e.g. eyes’ height) and
other positional variables can be observed (Nordfält 2007). How a choice is
positioned in the room is therefore relevant to human decision-making. It is
a widely known and practiced that the design of retail stores and the position-
ing of products has great impact on the choices of customers (Nordfält 2007).
The immense impact of positioning has been proven for all types of products.
However, few studies have been conducted on sustainability or health per se.
In general, it is reasonable to assume that the effect on sales of such products
should be comparable to any other product group. A Swedish example of
product positioning to influence default options is from Systembolaget (i.e. the
state-run monopoly stores for alcoholic beverages) to promote non-alcoholic
alternatives. Observations show that non-alcoholic beverages are advertised
in these stores and the non-alcoholic choice alternatives are often prominently
placed in the entrance area of the store, while strong alcohol is often in the
back of the store.
Norström et al. (2010) calculated the potential effects of replacing the
Swedish alcohol retail system with licensed private stores, which would increase
alcohol consumption in Sweden by 17%. The introduction of a free-market
system (i.e. alcohol sold in any retail store) would increase alcohol consump-
tion by 37.4%, leading to an additional toll of 2,000 deaths, 20,000 assaults,
6,600 drinking driving offences and 11.1 million days of sick leave per year.13
Provide information about others’ behaviour and ideal-type behaviours:
Humans seem to be greatly influenced by their social environment when it
comes to the type of food and the amount of food they consume. As reported
earlier, portion sizes greately affect the amount of food consumed, as well as
whether people dine alone or with company. According to Wansink (2004)
total food intake increases in line with the number of persons being present
at the table. A meal shared with one other person was found to increase total
intake by 33%, while a meal shared with seven or more people resulted in
13 Note that these results do not primarily address the product positioning and store design policies of
Systembolaget, but describe the broader effects of a regulated market for alcoholic beverages
Nudging – A tool for sustainable behaviour?
a doubling of intake. Following this study, it can be suggested that perhaps
individuals orient their intake according to those people eating the most
in a social context, and not those eating an average amount or lower than
average amounts.
How this can be used to achieve a pro-environmental outcome is docu-
mented in a study from Norway. Kallbekken and Sælen (2012) focus on food
waste and its implications for climate change. They placed a sign at the buffet
of seven hotel restaurants reading: “Welcome back! Again! And again! Visit
our buffet many times. That’s better than taking a lot once”. They thereby
introduced a cue about a normal behaviour, which resulted in 20,5% reduc-
tion of food waste compared to the pre-intervention data.
6.2.2 Critical success factors of nudging strategies
Several factors of success for nudging can be derived from literature about
food consumption reviewed for this report.
Most importantly, nudging individuals to consume food differently works
best in controlled environments. Numerous studies, for example, show sig-
nificant impact of nudging in canteens. Canteens, of course, are places with
a high level of unilateral control of one authority over the behaviour of con-
sumers. Where a school board, a city council or a company has the ability to
decide about most aspects of the consumption situation, with little or no inter-
ference by other actors, nudging can be effectively designed and implemented.
On the other hand, where the actor responsible for the nudge intervention is
not fully in control of the situation less success seems to be the result. This
becomes apparent in the discussion about the impact of nutrition labelling
on food packages, which seems to be undermined by the design of the rest
of the packaging. In Sweden, the controlled environment of the state-owned
alcohol stores (Systembolaget) allows for a level of nudging (for responsible
alcohol consumption) not achievable in a market dominated by privately run
retail stores where nudging efforts are counteracted by marketing efforts.
Systembolaget is therefore able to influence the point-of-sale environment
without other actors interfering in the choice architecture and can, among
others, encourage consumers to consider non-alcoholic alternatives or discour-
age excessive drinking. This system is effective in limiting alcohol consumption.
Second, there often seems to be a low willingness to invest a lot of effort
into the decision-making process. Consequently, humans show a strong will-
ingness to react to outside cues, and are in many cases happy to follow some-
one else’s choice for them if it makes their decision-making process easier and
faster. This can happen consciously (i.e. provide certain information to influ-
ence a decision), or unconsciously (i.e. manipulate the choice environment).
Salience has been shown to be of crucial importance for how individuals
choose the limited factors according to which they make a decision. However,
studies in food consumption also seem to point towards the importance of
predispositions to certain nudges. Where individuals carry a positive attitude
or desire for a particular behaviour but fail to follow this predisposition
in practice, nudges appear to be more effective than in situations where the
Nudging – A tool for sustainable behaviour?
individual is consciously opposed to certain behaviour. The impact of nutri-
tion labels on food packages is highest for individuals predisposed to react to
health-related information, while individuals not predisposed to react to such
information seem to be less influenced. Being aware of the target audience and
which nudges work for them should therefore considerably increase the impact
that can be achieved with a nudge.
6.2.3 Lessons learned for devising more successful policies
Despite increasing efforts, results in the two major areas of application within
the area of food – health and climate change – remain moderate. This is
partly due to the counteracting force of marketing, and partly due to the com-
plex and unpredictable reaction of individuals, e.g. (Wansink and Chandon
2006). While laboratory experiments and interventions both point towards
considerable potential of nudging in food consumption, real-life success of
nudging interventions has so far been very limited. Best results can be found
where nudging can be applied without the counteracting effect of marketing.
Examples are Swedish Systembolaget and school canteens. In both cases the
consumer is exposed to a very controlled environment in which few counter-
acting forces are available and where one authority can design the nudging
intervention. Public places with a relatively controlled environment are there-
fore better suited for nudging interventions than private places (such as super-
markets and people’s homes).
This is because nudging works better when a decision context can be
designed to encourage certain behaviour without the contradicting influence
of other factors. Indeed, in such situations it can be argued that nudging is
superior as a behaviour influence tool compared to legislative or fiscal tools.
A study from Finland, for example, showed that where schools implemented
a forced vegetarian day for all pupils the short-term effect was an increase
of pupils leaving school for lunch rather than eating at the school canteen
and – for those that ate at the canteen – higher plate waste (Lombardini and
Lankoski 2013). A study from Umeå in Sweden confirms these findings, with
almost half of all pupils choosing not to participate in school lunches for those
days where only vegetarian food was served (Arvola and Liedgren 2014).
Lombardini and Lankoski (2013) therefore suggest using nudging instead
of regulatory tools for such cases. However, where nudging can only be per-
formed in an environment of low intervention control (e.g. private homes )
or where many competing factors (i.e. marketing in the retail store) are acting
upon the individual, nudging cannot be expected to be as impactful.
Secondly, one can conclude that successful policy making to promote
sustainable food consumption requires an underlying acceptance for such
behaviour among the individuals addressed. Studies have shown that nudges
sometimes are least effective on those individuals whom they are primarily
aim to influence (e.g. obese individuals). Where individuals are nudged to eat
less meat but do not carry an internal conviction that this is desirable, evidence
shows that compliance is low. Nudging should therefore be preceded by infor-
mation and education campaigns in which individuals are convinced to support
Nudging – A tool for sustainable behaviour?
the underlying policy. A second aim with such campaigns should be to estab-
lish the social norms that are at the basis of some nudging interventions.
Finally, a sound understanding of the target audience is important to
design a nudge intervention. Many studies show impressive results for nudging
interventions. At the same time they are restricted to very limited sample sizes
and specific environments. Scaling up a nudge interventions will likely prove
disappointing unless sound knowledge of the target audience and the behav-
ioural environment are available.
6.3 Personal transport
Transportation is the area where facilitating “good behaviour” has been going
on for a long time, but where nudging as a concept has not been popularised yet.
The transport sector alone is responsible for up to 30% of household
emissions and its impact is expected to grow in the future following the
annual growth of 1,3% in terms of passenger kilometres recorded in the
period between 1995 and 2010 (EEA 2011).
The main challenge of private transportation is the heavy reliance on pri-
vate car use in many places, both in cities, in the sparsely populated areas and
countryside where there is no alternative to private car use. Therefore the focus
of shaping more sustainable mobility patterns heavily depends on provision of
infrastructure, products, processes and shaping environments that can com-
pete with the convenience of car use. However it has been challenging to find
an alternative that would offer equal functionality as the private car does espe-
cially in rural areas or in cases of longer or multi-leg journeys. Car use in urban
settings is also problematic due to the congestion problem. For example, the
largest share of trips are less than 4–6 km in the UK (Department for Transport
2011b). So together with greening the car fleet itself, for example by support-
ing the emerging market of electric and other types of low emission vehicles,
there is a need to facilitate change in people’s transport behaviour and their
perception about mobility and its alternatives.
An important question is of course who should facilitate the change.
Existence of two market failures in transport warrants, according to some
researchers (Metcalfe and Dolan 2012), the government to change behav-
iour. The first market failure is the failure to incorporate environmental
externalities into the price of fuel and the second one is the information bar-
riers and transaction costs that hinder people from behaving in a better for
them way, e.g. driving safely, economically or in an environmentally sound
manner. To address these market failures, typically a broad range of measures
that target transport related patterns and levels of mobility consumption are
developed (Figure 5).
Regulatory instruments often face implementation and public acceptance
problems; even financial instruments meet strong resistance, as demonstrated by
the strong public rejection of the UK fuel tax escalator (Dresner et al. 2006),
Nudging – A tool for sustainable behaviour?
the congenstion charges in Manchester (Ahmed 2011) and the Edinburgh
road user charge (Gaunt et al. 2007).
In Figure 5, nudge approaches are situated in the middle of the ladder and
represent one element of a diverse set of options that target transport behaviour
and that sometimes are put together in policy packages.
Eliminate choice: regulate to eliminate choice enrely
Restrict choice: regulate to eliminate choice enrely
Guide choice through disincenve: use nancial or other
disincenves to inuence people to not pursue certain
Guide choice through incenves: use nancial and other
incenves to guide people to pursue certain acvies
Guide choice through changing the default: make
‘healthier’ choices the default opon for people
Enable choice: enable people to change their behaviours
Provide informaon: inform and educate people
Do nothing or simply monitor the current situaon
Greater levels of intervenon
Figure 5 Ladder of interventions (Nuffield Council on Bioethics 2007)
Such packages include a wide range of tools from information provision, to
shaping the infrastructure and the environment in which transportation takes
place, to changing defaults in car designs and applications to enable and
facilitate road safety and more environmentally sound driving habits, as well
as changes in urban planning to reduce the need for travelling, such as the
10-minute city, where people have access to various services they may need
in daily life within a 10-minute walking/cycling radius. Devising policy pack-
ages is considered to be an important factor in successful transport policy (see
more on success factors in section 6.3.2).
6.3.1 Evidence for the effectiveness and efficiency
Despite the long history of transport policy and proliferation of various sys-
temic approaches to addressing problems of access, congestion and environ-
mental pollution, e.g. total mobility management or Integrated Transport
Policy, there are few specific studies that evaluate the effectiveness of individ-
ual behaviour change strategies in private mobility (Tørnblad et al. 2014). On
the other hand, total mobility management programmes have been evaluated
and typically show between 5% and 15% reduction in car use both in the
short and long term (Brög et al. 2009; Chatterjee 2009).
Nudging – A tool for sustainable behaviour?
However, when it comes to specifically nudges, other researchers also confirm
that “[a]pplications of the nudge approach to transport have not been tested
in a large scale or systematically analysed in transport contexts. Therefore
their effectiveness remains an open question” (Avineri and Goodwin 2010;
Metcalfe and Dolan 2012). On the other hand, the interest in design and
implementation of alternative or supplementary softer policy instruments is
growing (Avineri 2012). These soft measures in transport sector aim to change
traveller behaviour by “altering their perceptions of the objective environment,
by altering their judgements of the consequences associated with the use of dif-
ferent travel options, and by motivating and empowering them to switch to
alternative travel options” (Bamberg et al. 2010).
Table 6 Nudge mechanisms used to influence consumption of mobility14
Nudge mechanisms used Applications to mobility Evidence of effectiveness
Simplification and framing of
Decluttering streets, providing
clear information, maps and
changing framing to encour-
age cycling and walking,
offering cycling training or
personal travel plans, simplify-
ing information on fuel con-
sumption of cars
Average reduction of CO2
emissions by 19% among ten
travel feedback programmes
and up to 35% in some cases
Australian studies report 10%
reduction of car use via
personal travel plans14
Changes to the physical
Road and lane planning,
urban design
Effective as infrastructural
projects and systemic
Changes to the default option Auto-pilot decisions in cars,
road planning, helmet wearing
Effective, e.g. dynamic speed-
limits that reduced speed
driving from 70% to 17%
in Linköping.
Use of descriptive social
Travel or walking feedback
programmes where social
norms and social networks
are involved
Smartphone apps to encour-
age physical activity
Mixed evidence of effective-
ness and low validity due to
low sample size. In one study
the app users increased their
walking by 64% for a period
of time.
Framing of information is important since behaviour depends to some degree
on how the situation is presented or with what words the issue is formulated.
A study by Larrick and Soll (2008) exemplifies the framing effect on people by
showing how drivers consistently misunderstand miles per gallon as a measure
of fuel efficiency, which leads to that they undervalue small improvements on
inefficient vehicles. If the standard “miles per gallon” was changed to “gallons
per mile” would help drivers to know exactly how much fuel they use on each
trip or during a certain period of time.
14 Reduced car use is associated with increased use of public transport, walking and cycling Socialdata
(2004), TravelSmart travel surveys, Socialdata Australia Pty Ltd. and Ker, I. (2004), ‘Household-based
voluntary travel Behaviour change: aspirations, achievements and assessment’ Transport Engineering in
Australia, Vol. 9 No. 2, pp. 119–138.
Nudging – A tool for sustainable behaviour?
This could be then linked with the help of some additional information to the
amount of CO2 emissions from each trip. In addition, the “gallons per mile”
helps people to calculate cost savings from reduced fuel consumption. The
results of better framing can be seen from the evolution of the fuel economy
stickers in the U.S.
Choice of transportation mode. Previous successful strategies to change
people’s choice of transport mode from e.g. private car to public transpor-
tation have focused on targeting people at “life changing” moments, when
people are moving from one place to another or expand their families. People
can be nudged towards certain choices with simplified information, higher
salience of certain features of alternative transport means or financial and
other service offers. Provision of sustainable transport options is also a factor
here. For example cargo bikes are now available in many cities, e.g. Malmo,
and this makes it possible for people to use a bike where before only a car
was possible.
Feedback on transport use and mobility patterns, i.e. provided through
apps, comprise travel feedback programmes, including bicycling and/or walk-
ing. These programmes use personalised communication to change mobility-
related behaviour, which may include personal communication and feedback
between participants and experts. One study reviewed ten travel feed back
programmes, mostly from Japan, and concluded that the average reduction
was 19% of CO2 emissions from transport with some travel feedback pro-
grammes reporting as high as 35% reduction of CO2 emissions (Fujii and
Taniguchi 2006).
Changing the physical environment have been reported as one of the most
effective instruments to influence travel behaviour, especially in combina-
tion with other instruments (Pucher and Buehler 2008; Gössling 2013), for
example, road planning with lines, colours, signs and humps that may greatly
influence driving speeds, driving patterns and in general guide the flow of traf-
fic. For example, toll stations at Öresund bridge between Copenhagen and
Malmö have experienced difficulties with
controlling speed limits – 200 000 cars
(4% of all cars) drove 40 km/h where the
speed limit was 30 km/h. They have now
installed dynamic speed limits Actibump-
system that go down by 4 cm if cars drive
faster. The 3-year long experience with
Actibump-system from Linköping show
that where 70% of cars drove faster than
the speed limit before only 17% do it now
(Jacobsson 2014).
Similarly, the location of parking lots and bicycle stands creates a powerful
signal to all the participants in traffic. Instead of car parking being usually the
closest parking to the entrance/exit doors, placing bicycle parking visibly near
the door, then the car-pooling and sharing, then perhaps the electric vehicles
Figure 6. Changing in the physical
environment (Foto: O. Mont)
Nudging – A tool for sustainable behaviour?
and only then the parking spaces for other cars could send a powerful signal
about what travel mode is preferable and encouraged by the infrastructure.
Additional services can also enable more sustainable transport choices for
people. For example, Skånetrafiken offers apps for easily accessible maps and
the possibility to order individual bus or taxi for the “last mile” in sparsely
populated areas, thereby encouraging people to take the train and comple-
menting it with additional and often customised service.
Feedback on driving patterns Another type of feedback can be offered to
drivers through in-vehicle data recorders with the purpose of rewarding vari-
ous behaviours that are considered good for road safety, the environment or
for other pro-social reasons, e.g. driving within speed limits, keeping sufficient
distance to other vehicles, soft rather than fast acceleration and deceleration.
The use of this technology has been shown to be popular amongst the public
especially when it is used together with financial incentives, e.g. paid by insur-
ance companies. Interestingly, the popularity of the measure has been the
highest among drivers with more aggressive and risky manner (Musselwhite
2004). One study found that providing drivers with feedback on dangerous
driving behaviour reduced accident rates in the short term (Toledo et al. 2008).
Creating positive social norms about more sustainable travel modes is
important. For that various mechanisms could be used, from traditional
advertising focused on deliverying pro-social messages15 to employing nudges
that are built on descriptive social norms making people aware of how others
are travelling.
Other types of behaviour change strategies include training in cycling or
eco-driving. However, these approaches primarily affect the reflective side of
our behaviour, unless they become habitual with time.
One of the fast-growing methods for influencing mobility behaviour indi-
rectly is by encouraging walking with the help of smartphone apps. A growing
number of such health-oriented apps allow people to set personal goals in
terms of e.g. steps taken per day, routes, distances and walking speeds. Using
the social norm approach they often include mechanisms for sharing the pro-
gress with other users (online community) or with friends and family and for
facilitating social influence by inviting other users to take part in competition
with each other. Some of these apps also provide the users with moral approval
of good behaviour, e.g. through introducing avatars whose wellbeing depends
on the performance of the user. Evidence of the effectiveness of these apps in
promoting physical activity is mixed and is usually measured in small groups,
which undermines the validity of these evaluations. In one study of 152 males
using an always-on accelerometer-based smartphone app, the app users
increased their walking by 64% (Harries et al. 2013).
15 See an example of a Danish ad promoting travelling by bus as cool: Epic Bus Ad from Denmark –
Nudging – A tool for sustainable behaviour?
6.3.2 Critical success factors
Success factors vary depending of the type of nudge strategy related to trans-
port behaviour. In general, however, also in transport sector the best working
solutions comprise several policy instruments that work synergistically. Below
not only success factors are discussed, but also the factors that make it difficult
to develop policy instruments that target travel behaviour.
Policy packages to promote better choice in private mobility are con-
sidered a critical success factor since the mobility behaviour is complex and
influenced by a great number of parameters, starting from where the location
of home, the daily routines of people and the transport options offered by
public and private actors (Department for Transport 2011b). For example, in
one UK project three towns invested in packages of soft and hard measures to
promote sustainable travel. The soft measures included information provision
and marketing to encourage people to use more sustainable transport choices,
while hard measures comprised improvements to infrastructure and public
and private services. In these three towns, the following results were reported
in the household survey and traffic counts (Department for Transport 2011):
The distances driven were reduced by 5–7% per resident;
Overall reduction in traffic was about 2%, and 8% in inner city;
The use of bus and other public transport modes per resident were
increased in two out of the three towns by 14%;
The number of trips by bicycle increased by 26% per resident;
The number of walking trips per resident increased by 13%.
Such results have not been observed in similar towns without the packages of
sustainable transport measures that were introduced in the abovementioned
The same success factor is mentioned in studies on increasing bicycle use
in urban settings. For example, a review of 139 studies of programs promoting
bicycle use in cities demonstrate a great variety of tools that are typically used
over a long period of time that in combination lead to significant increases of
bicycle use. Compare, for example, the 38% share of trips made by bicycles in
Copenhagen (Gössling 2013) to 1% of trips in the UK and the USA (Pucher
and Buehler 2008). The combination of these measures include: “on-road
bicycle lanes, two-way travel on one-way streets, shared bus/bike lanes, off-
street paths, signed bicycle routes, bicycle boulevards, cycletracks (separated
by kerb from other traffic infrastructure), coloured lanes, shared lane mark-
ings, bike boxes (also called ‘advanced stop lines’), bicycle phases/traffic sig-
nals, maintenance of infrastructure, wayfinding signage, techniques to shorten
cyclists’ routes, traffic controls/traffic calming, … car-free zones, … bike park-
ing, bicycle stations, parking at rail stations, parking at bus stops, bike racks
on buses, bikes on rail cars, short-term rental bikes, and showers at work-
places” (Gössling 2013 p. 197).
Critical success factor for the travel feedback programmes seems to be the
possibility for the participants to create their own implementation plans (Fujii
Nudging – A tool for sustainable behaviour?
and Taniguchi 2006). Face-to-face meetings with personal travel guides and
soliciting customised assistance has also been identified as an important factor
of success for changing travel behaviour.
Sharing information about travel services combined with the social norm
function was highlighted as a success factor by Bartle et al. (2011). In this
study the process of information sharing among cyclists commuters through
a web-based interactive service was studied. The site not only shared factual
informaton, but also offered social networking among the commuters. The
social function allowed reinforcement of positive views of cycling as a com-
muting mode among the commuter group members.
6.3.3 Lessons learned for devising more successful policies
The main lesson from the existing knowledge on the use of nudge in travel
behaviour is the lack of studies that can discern the effectiveness of specific
mobility management instruments. Consequently, more research is needed
both on the effectiveness and efficiency of individual instruments and on their
synergetic effects.
When it comes to the use of nudges, the UK Department for Transport
(2011) highlights that limitations in the use of nudges to facilitate changes
in travel behaviour are due to a great variety of factors influencing behav-
iour. The same person may react differently to the same influencing factor
depending on the role the person assumes at a given moment (Department for
Transport 2011a). Indeed, there is compelling evidence on the great hetero-
geneity of people’s responses to behaviour change policy tools in transport.
Therefore, more research is needed on the diversity of decisions with regard
to travel choice making and concerning people response to different policy
meausures. In doing so, policy makers and transport planners may rely on
traditional segmentations of people according to their socio-demographic and
attitudinal parameters (e.g. attitudes towards sustainable transport modes),
or they could also solicit research on identifying segments of people that are
most likely to change their behaviour if targeted by policy measures developed
based on insights of behavioural science.
People also react differently to the same factor but in different contexts.
So some researchers warn about the limitations to directly transfer findings
on the application of behavioural sciences to transport from other domains
since the context of choice making in transport might be different from choice
making in other environments (Ert and Erev 2008).
Another challenge associated with the transport domain is to devise poli-
cies that encourage pro-environmental and pro-social behaviours of individu-
als even though the environmental externalities of travelling can be seen as
a social dilemma, rather than an individual problem. This means that in the
transport domain people might not have as strong drive to reduce environ-
mental impact as in energy or food domains. In this case, policy makers can
draw on other features of human behaviour, such as people’s tendency to “do
Nudging – A tool for sustainable behaviour?
the right thing” (Dawnay and Shah 2005), to “act appropriately” (Lindenberg
and Steg 2007) or to consider health-related aspects.
When it comes to the power of framing, loss aversion is one of the strong-
est mechanisms that affect the way people respond to different policy inter-
ventions. Framing messages in negative terms has higher effect than framing
them in positive terms. Therefore, loss framing can be incorporated into
policy design to influence people’s behaviour, including personal carbon calcu-
lators, journey planners, and customised travel information provided to indi-
viduals (Waygood and Avineri 2011).
Some lessons can be drawn regarding the research design of many studies
conducted in transport domain. Specifically, claims of large effects have been
criticised on several grounds. To start with many of the empirical studies inves-
tigate effects of total mobility systems that contain a mix of command-and-con-
trol instruments, economic incentives and soft measures comprising information
provision and nudge-like instruments. Many of the reported studies fail to
provide consistent record of how the field research was done, and often lack
adequate control groups (Friman et al. 2013; Tørnblad et al. 2014). Therefore,
researchers call for further controlled experiement on the effectiveness of both
total mobility management programmes and of individual instruments.
Nudging – A tool for sustainable behaviour?
7 Nudge as practical application
7.1 Designing policy interventions with
behavioural insights
Practicing nudge by developing and implementing policies taking into consid-
eration behavioural insights is a process that takes time. It also places a high
demand on knowledge of existing evidence about human behaviour and about
behavioural patterns in specific contexts and requires resources for reviewing
available evidence on different interventions, for choosing interventions that
are best suited for the set goal and for devising more effective policies and
instruments. Designing nudge policy instruments is thus not always the cheapest
way to a more efficient policy making.
Literature offers a great diversity of models for how to design policy inter-
ventions based on insights of behavioural sciences. One of the most popular
models is the “The nine principles” model developed in the UK by Darnton
(2008) that draws on findings from behavioural modelling and prescribes an
iterative cyclical process in policy development and application.
The process of moving from step to step is iterative, meaning that insights
from later steps might imply revision of the earlier assumptions and steps.
The circle represents the idea of “learning by doing” where the interventions
are being continuously refined as a result of ongoing monitoring and evalua-
tion (Bonsall et al. 2009).
Interrogate models/
identify key factors
Agree objectives/
success measures
Interrogate evidence
on interventions
with ‘actors’
Pilot and monitor
Evaluate pilot/
final intervention
learnings back in
Figure 7 A framework for devising policymaking based on behavioural
insights and aiming at behaviour change (Darnton 2008)
Nudging – A tool for sustainable behaviour?
As shown in Figure 7, the framework involves the following nine steps (steps 2
and 3 are collapsed into one step):
1. identify the audience groups and the target behaviour. If behaviour is
too complex it should be broken into simple behaviours or elements.
2. identify relevant behavioural models including both individual and
societal models and make a short list of the most prominent influencing
factors. This step may involve literature review or consultation with
3. select the key influencing factors and use them to develop objectives for
the intervention strategy/policy option.
4. identify effective intervention techniques that have worked and were
effective in the previous interventions that targeted specific influencing
5. engage the target audience for the intervention in better understanding
their behaviour and the influencing factors from the user/target audience
6. develop a prototype intervention and evaluate it against relevant policy
frameworks and assessment tools.
7. pilot the intervention and monitor the results (see below an overview of
8. evaluate impacts and processes against the objectives developed in step 3
linked to the factors influencing behaviour.
9. feedback the lessons learned in order to deepen understanding of the
intervention and the target behaviour.
The types of interventions mentioned in step 4 could be regulatory and coercive
instruments, fiscal incentives and disincentives and soft policy tools, including
information-based instruments and the nudge toolbox consisting of defaults,
improving salience of information, changes in physical environment and engage-
ment of social norms in behaviour change.
In order to evaluate which policy interventions are most effective, efficient
and accepted by the public, a range of research methods can be used. Their
choice depends on the purpose of the policy intervention, the target audience
and other factors, e.g. context. In principle, there are four types of methods
that are often used to test behavioural change and to collect insights about
policy interventions : experiements, randomised controlled trials, surveys and
qualitative research (described below). Each of them has its own strengths
and weaknesses (see Table 7).
Experiments are usually conducted in controlled environments with closely
monitored parameters and carefully chosen small sample of subjects. Due to
these design parameters, they tend to provide consistent and reliable results
that can be replicated in different places and times. In a typical experiment,
change in behaviour of two sets of subjects (control group vs. treatment group)
Nudging – A tool for sustainable behaviour?
is compared. A researcher first changes one parameter that might be similar
to policy intervention, e.g. provision of information or fiscal incentive, and
then measures changes in the behaviour of studied sample of people (treatment
group). The changes would then be compared to the control group. In this way
one can draw conclusions on the effect the changed parameter has on actual
behaviour of participants. The control of the parameters secures that experi-
ments are typically systematic and rigorous, which often gives the possibility
not only to establish correlations (typical for surveys), but also cause-effect
relations. In experiments researchers can achieve statistically significant results
from small samples, which is cost-efficient. However, experiments may have
the problem of low generalisability outside the laboratory (van Bavel et al.
2013) since the outcomes of experiment might depend on the external factors
and not only on the parameters controlled in the experiment itself.
Randomised controlled trials (RCTs)
RCTs are another research method established in applied behavioural science
in which interventions are tested experimentally in their natural environment,
wherever it might be – in a shop, at home or on the street. RCTs typically
devide research subjects into two groups, where the treatment group faces
changes in one or some parameters, while control group maintains status quo
or receives the equivalent of a placebo. The outcomes of RCTs often depend
on the target group, specific location and time of the RCT execution. Similar
to experiments, RCT face the problem of generalisability to other contexts,
since the effect of particular interventions can depend on the context (Pawson
and Tilley 1997). It is often recommended to run RCT twice to make sure that
revealed causal relations between parameters and behaviours are true. This of
course increases financial costs and makes RCTs a time-consuming enterprise.
Surveys have been widely used in supporting policy making and are based on
questioning large samples of people about their behaviour. One of the strong
sides of surveys is their external validity as the sample is typically representa-
tive of the larger population. On the other hand, surveys are usually designed
with limited range of information to be collected, as many answers are pre-
formulated leaving little room for flexibility and extensive comments from
surveyed subjects. Surveys also offer little possibility to check the truethfulness
of the answers and it is typically difficult to monitor whether people respond
honestly or offer socially accetable and politically correct answers. Finally,
self-reporting of behaviour implies that information provided is subjective, as
experienced and perceived by the surveyed subjects and might substantially
deviate from the actual behaviour. Especially when dealing with behaviours
that people are not conscious of, surveys do not offer reliable findings con-
cerning behaviour.
Nudging – A tool for sustainable behaviour?
Qualitative research
A range of research methods that are commonly used by behavioural scientists
and to some extent in policy evaluation are interviews (open ended and semi-
structures), focus groups, and participant observation. These methods collect
rich data about behaviours, opinions and feelings of studied subjects and
much deeper accounts of events and various phenomena. Unlike in the case
of surveys, interviewed or observed subjects are not restricted by the set of
pre-formulated questions and are typically free to generate their own insights.
Observations also typically take place in natural environments thereby giving
people freedom to demonstrate actual behaviour. Qualitative research is usu-
ally done on small samples of subjects, which affects its generalisability to the
level of entire population. On the other hand, the small sample size makes
these methods cost effective.
Table 7 Summary of types of behavioural studies (van Bavel et al. 2013)
Type of study Pros Cons Minimum
time horizon
Experiments Can establish causality, not only
Can provide statistically significant
results from a relatively small
sample size
Representativeness for
EU-28 not feasible
A laboratory is an unrealistic
and artificial environment
6 months
control trials
Core findings can apply to other
Can establish causality, not only
Allow for observations in natural
Very expensive to run at EU
level (and to replicate in
order to validate results)
Results from one location not
generalisable to others
12 months
Surveys Representativeness for EU-28 is
feasible; relatively cost effective
Respondents are limited by
pre-established options to
Respondents might not be
Only gather data on self-
reported behaviour
Cannot establish causality,
only correlation
4 months
Provide richer, more nuanced data
about behaviour
Often take place in realistic
Participants are given freedom to
express themselves, with limited
intervention by researcher
Data collected is generally
not representative of the
larger population
Usually have small samples
due to the time and cost
4 months
To summarise, qualitative methods are best suited for uncovering the diverse
representations and expressions of the studied behaviour and the factors that
affect it, while quantitative methods are best suited if the goal is to establish
the prevalence of certain behaviours among a population.
Nudging – A tool for sustainable behaviour?
The behavioural insights gained with the help of these research methods could
be used at different stages of policy development process (van Bavel et al. 2013):
1) at the design stage when potential response of people to various elements of
policy need to be examined and various policy designs tested; 2) at the Impact
Assessment stage when decisions are made about mechanisms to introduce,
enforce and monitor policy implementation. 3) The implementation stage may
include experiments or pilots that could assist with choosing the most effec-
tive and cost-efficient policy options. Once a particular policy intervention has
been decided upon, a behavioural pilot study could be conducted in order to
test policy effectiveness on a smaller sample of people before its full-scale roll-
out. The involvement of behavioural scientists in pilots and rolling out of poli-
cies is critical and there is need to integrate them much earlier upstream in the
policy design stage. The small scale pilot may offer insights on behaviour that
have not been anticipated earlier. This might mean that policy process may
need to go back one step to the policy design stage (Figure 7). Thus, nudge is
not a discrete action but a process where adaptation/ evolution of behaviour
changing tools is planned for and where follow-up action is possible (House
of Lords 2011). 4) Finally, behavioural insights are not only relevant in shap-
ing new policy instruments, but also in ex-post evaluations of existing policies.
7.2 Nudge in the policy toolkit
Behaviour change is a complex system under influence of numerous societal
interactions; therefore changes to behaviour require complex approaches.
Nudging in itself is an array of specific nudge tools, and it is an addition to
the policy toolkit for changing behaviour and in particular, a tool to make
policy implementation more effective (as in the UK BIT examples). More
importantly, it highlights the critical role of the context for decisions/behav-
iours of individuals. Therefore, nudge strategies and tools themselves need to
be accompanied by other measures that, for example, create pro-sustainable
values or offer sustainable infrastructure.
This in turn means that nudge is one tool out of many that are needed in
order to change consumer behaviour in pro-sustainable directions and it needs
to be supported by infrastructure and institutions so that the very context of
the behaviour would promote the behaviour itself, e.g. information about
the benefits of cycling to work are communicated while new cycling facilities
are being provided. Studies indicate that combination of policy instruments
improves behaviour change outcomes. For example, Dolan and Metcalfe
(2011) report on a large field experiment in which they compared the effects
of social norm communication on energy saving with effects achieved when
social norm communication was linked to information on energy saving. The
application of the combined tools doubled the effect. Thus, often the role
of nudging in the policy development and application is to supplement and
enhance effects of other instruments, e.g. through increasing salience of infor-
Nudging – A tool for sustainable behaviour?
mation, by complementing eco-lable with life cycle costing (GreeNudge 2013)
or by combining effects of social norms with information provision.
So, in which policy applications can nudge be an interesting policy tool?
In principle, any policy directly or indirectly influences behaviour of people
or has a behavioural element to it could benefit from using insights of behav-
ioural science and where relevant, the nudge tools (van Bavel et al. 2013).
Nudge may provide useful input at different stages of policy development and
implementation process, from idea generation to execution and ex-post evalu-
ations, explaining outcomes and perhaps offering valuable clarifications as to
behavioural and contextual factors that affected the results. It can be useful
both for designing new policies and for evaluating the effectiveness and effi-
ciency of the existing ones.
So for which types of policies can one expect nudge to offer a useful con-
tribution? Behavioural insights and nudge specifically can be relevant for
policies that directly aim to (Lunn 2014):
1) change specific behaviours, for example, wear seat belts, use condoms,
waste less food or quit smoking or drinking (van Bavel et al. 2013),
2) address low-involvement products and spontaneous purchases (sugar, soft
drinks) or
3) policies that target relatively complex products and services, such as finan-
cial services, health insurance and other markets involving service con-
tracts, as well as such diverse areas as online gambling, transparency of
bank charges, European sales law and fees for international credit card use.
In addition, nudge tools can be useful for the policy making process per se,
since policy makers are also subject to biases, cognitive short-cuts, and are
influenced by social norms and group pressure as much as other people are
(van Bavel et al. 2013). Raising awareness about these pitfalls can reduce
their negative effects and improve policy design and, in the best case, policy
effectiveness (Lunn 2014).
7.3 Institutionalising nudge in policy context
As briefly outlined in chapter 5, the policy application of insights from behav-
ioural economics and cognitive psychology has been organised in different
ways in various countries. For example, in the USA, behavioural insights
were first applied in regulatory review, with a strong focus on evidence-based
policy. However, more recently, the approach has turned more to in-house
consultancy work, where administrations gain training, research support and
networking. In the UK, the Behavioural Insights Team was originally established
in the Cabinet Office, but has been recently divested into an external consul-
tancy, which however mainly (but not only) works for the Cabinet Office and
hence the central government. In Denmark and Norway, nudge activities were
originally established outside government and to serve a broader clientele.
Nudging – A tool for sustainable behaviour?
If the work with nudge should be given specific attention in Sweden, what are
the prospective ways to institutionalise such an effort in the Swedish policy
context that would allow:
1) integration of behavioural insights throughout policy making process
(from idea generation to design, implementation and evaluation) and
2) testing and improvement of policy effectiveness and efficiency in vari-
ous sectors of policy making, e.g. environmental, consumer, waste man-
agement, financial and health services. Several ways to organise work on
nudging are conceivable:
A unit within the state administration or supporting institutions,
e.g. agencies
A research team at a university or research institute
An independent consultancy company working with nudge
experiments and policy testing
Each of these institutional arrangements has its strengths and weaknesses.
However before choosing an institutional form for incorporating the insights
of behavioural economics in Sweden, perhaps a roll-out of knowledge and
experience to other administrations (besides the Swedish EPA) could be useful,
which could help set up a network of people interested in nudge and its appli-
cations and/or who could be involved in the future work.
In addition to the establishment of a unit providing support for the devel-
opment and testing of nudges, there might be a need to create demand and
capacity for this kind of expertise within the public administration. Hence,
training events, capacity building and/or networking might be helpful for
the relevant administrations (consumer, environment, transport, food, public
health, housing, energy etc.). For example, each administration might want
to select a “nudge contact person” and “nudge network” meetings might be
organised for these contact persons to hear experts and share experiences,
insights and ideas.
A broader deployment of nudge within the public administration might
also require political discussion. This might, for example, be a task for the
nudge network to prepare and present for Parliament. Going ahead, it might
also be relevant to engage municipal administrations, as the municipalities
provide a wide range of services in general and relevant to sustainable con-
sumption in particular.
Nudging – A tool for sustainable behaviour?
8 Conclusions
Insights from behavioural sciences are being increasingly used to inform policy
making. Examples include the simplification of complex environmental or
sustainability information through the use of eco-labels, improvement of the
salience of health impacts of foods through standardised nutritional informa-
tion, or offering people higher levels of convenience by providing them with
close-to-home recycling facilities. Lately, the focus on applications of behav-
ioural economics such as nudge, have been helping policy makers in different
countries and sectors to more systematically integrate behavioural insights
into policy design and implementation in consumer and competition policies,
especially when it comes to providing default options in situations with com-
plex information (e.g. pension funds or financial services), simplifying com-
plex information for users or mandating economic actors to provide certain
information. Also making key information more salient or making preferable
options more convenient for people have been widely employed.
Although scientific evidence underpins many of the policies informed by
behavioural economics, the size of the effects of policy interventions and the
actual outcomes of interventions in specific contexts remain hard to meas-
ure. Results from one experiment cannot be indiscriminately generalised to
a different context or to a wider population. The problem is the complexity
of human behaviour and the diversity of factors that influence it. Thus, even
when it is possible to demonstrate visible or significant effects of a certain
intervention, the precise causal mechanisms between the revealed subtle influ-
ences are hard to identify in real-life contexts. This means that the policy impact
might be hard to estimate ex-ante even in the presence of sound empirical
findings. Therefore policy makers need to pay close attention to the size and
relevance of an effect that might be obtained from a specific policy interven-
tion in a specific context (i.e., concerning a specific behaviour, a specific target
group, at a particular time, and in a localised geographical context). Policy
outcomes are always context dependent.
Despite the relatively uncertain outcomes in specific local contexts, the
use of the inductive approaches of behavioural economics, such as nudges, is
growing in some countries. These approaches are seen as a complement to the
traditional policy instruments rather than as a substitute for coercive measures
(laws and regulations) and economic tools (e.g. fiscal incentives, subsidies,
taxes or fees). Nudging in general and green nudges in particular are interest-
ing tools that can be used alongside other instruments for behaviour change
(Centre d’analyse stratégique 2011). Especially in recent years, when there is
a growing understanding of the importance of policy packages, nudge tools
are being increasingly applied in combination with legal and fiscal instruments,
for example in the case of smoking and wearing car belts. Nudge is a useful
strategy for inducing changes in context-specific behaviour. Rather than being
seen as a silver bullet, the largest promise of nudge is perhaps in helping design
other initiatives better and in improving the effectiveness and efficiency of
Nudging – A tool for sustainable behaviour?
policy tools and the speed of their implementation (Avineri and Goodwin 2010).
Nudge is a cost effective instrument that enhances other policy tools and targets
behaviours that are not addressed by other policy instruments because the
behaviours are based on automatic, intuitive and non-deliberative thinking.
Nudging promotes a more empirical approach to policy design and evalu-
ation than the tools usually applied in policy making and ex-ante evaluation.
Cost-benefit analyses and regulatory and sustainability impact assessments
are conducted in a more deductive way, where the gathered evidence is sieved
through a theoretical framework in order to offer a reliable estimate regard-
ing the expected effects of a certain intervention in a middle to long term. The
behavioural economics approach relies on a much more dynamic interplay
between theory, evidence and policy relevant outcomes. Theoretical knowledge
about behaviour change may help generate a range of options for how to help
various actors make better choices, but the policy-relevant outcomes – the
effect of the different interventions – will nevertheless depend on the specifics
of the context tested empirically. Thus, in order to assess the effectiveness of
a policy intervention in a specific context, policy makers and regulators will
have to employ experiments, pilots or randomised control trials, in addition to
cost-benefit analysis, regulatory and sustainability impact assessments.
An important consideration for tools based on the findings of behavioural
economics is their acceptance by the public. This depends, among other issues,
on whether the targeted behaviours are controversial or not. Here social
norms and values play a role. For example, policy tools that are designed
to change the way information is presented to the users by simplification,
improving the salience of certain features or increasing the level of conveni-
ence are less controversial. This is because they help people avoid clearly
identifiable mistakes they are prone to make due to lack of understanding of
complex information or due to paying attention to issues of lower relevance.
Other tools, such as defaults, might be more controversial to apply.
Public acceptance for different nudge tools is easier to gain if there is
consensus regarding the “ends” of the policy intervention – its goals, e.g.
improved road safety. However, when there is no common agreement about
the goal of the policy intervention, which might be the case for e.g. risky
investments or gambling, high impact consumption or wasteful behaviour, it
might be difficult to gain acceptance for specific measures, even though the
goals of such interventions could have been accepted by the public.
One of the substantial limitations of nudge in the sustainable consumption
field is the very fact that it works through influencing intuitive and non-delib-
erative processes of individuals and thus does not actively engage the public
in debating patterns and levels of consumption. This also means that perhaps
this is a possible strategy for people with low engagement in sustainable con-
sumption and sustainability discourse. There is a growing consensus that “the
best interventions will certainly be those that seek to change minds alongside
changing contexts” (Dolan et al. 2012).
Nudging – A tool for sustainable behaviour?
Nudge is an appropriate tool for small choices and behaviours that can be
influenced at the level of detail required for designing better “choice architec-
tures”. Even in these cases – as in the case of all policies – there might be unin-
tended (positive or negative) consequences (Shove 2010). Broader systems,
such a the transport system of a city or a country’s reliance on fossil fuels are
not likely to be manageable at such a level of detail, and they are decisive for
the sustainability of consumption patterns. Hence, “nudge” is only one tool to
make policy measures more effective. In the case of sustainable consumption,
there is also a need to understand the deeper and more societally embedded
roots of unsustainable consumption. This can enable work on interventions
that shape sustainable infrastructures, enlist citizens to create new meanings
for them and develop new competencies (Shove 2012). The depoliticised
nudge paradigm is not likely to support such broader social and institutional
mobilisation for sustainable consumption.
The reliance on behavioural economics and its empirical approach in the
policy context has implications for the set of skills required in order to com-
mission, conduct and interpret the empirical assessments, both for policy
makers and regulators, as well as for the type of scientists to be charged
with the task of running the empirical tests and assessing the effectiveness of
various policy options to change behaviour. To assist with this, one useful
approach could be to organise a brainstorming session between researchers
and the staff of the Swedish EPA with the purpose to identify:
Existing successful and less successful experiences of explicitly or
implicitly using nudge in the Swedish context
New ideas for policies to be developed and later selected for testing
Suggestions for reforming existing policies, to be subjected to testing
and experimentation.
Finally, nudging is not a well-developed theory, but rather an application of
a broad range of behavioural sciences to public policy. As the application field
develops, the need for a coherent theory becomes more apparent and acute.
Experts in nudging indicate that specifically the interaction between delibera-
tive and non-deliberative systems of thinking need to be further explored.
With regard to specific consumption domains, future research could benefit
from more experimentation and piloting in the field of mobility and travel
behaviour, as there is much less research available in this domain than in
energy and food domains.
Nudging – A tool for sustainable behaviour?
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Swedish EPA SE-106 48 Stockholm. Visiting address: Stockholm - Valhallavägen 195, Östersund - Forskarens väg 5 hus Ub, Tel: +46 10 698 10 00,
fax: +46 10 698 10 99, e-mail: Internet: Orders Ordertel: +46 8 505 933 40, orderfax: +46
8 505 933 99, e-mail: Address: Arkitektkopia AB, Box 110 93, SE-161 11 Bromma. Internet:
The authors assume sole
responsibility for the con-
tents of this report, which
therefore cannot be cited
as representing the views
of the Swedish EPA.
A tool for sustainable behaviour?
Nudging is a tool that can be used for enabling behaviou rs
and private decisions that are good for individuals and
often for the society as well.
Nudges do not try to change one’s value system or
increase information provision. Instead they address
routine behaviours or situations with complex informa-
tion by offering default options, by making key infor-
mation more salient, by simplifying complex informa-
tion for users, or by changing the physical environment
to make preferable options more convenient for people.
This report was written by researches from Lund
University. The study builds on literature analysis of the
existing body of knowledge on nudging approaches in
different policy contexts and in different countries. The
report analyses the existing evidence with regard to the
role, limitations and the varying degree of success of
nudging in three domains of household consumption:
energy use in the home, food and personal transport. It
then describes potential avenues for employing beha-
vioural science in policy making.
ISBN 978-91-620-6643-7
ISSN 0282-7298
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... It can act as a 'nudging' tool in the catering establishment (Mont et al., 2015). The food consumption pattern is difficult to alter as it is voluntary (Mont et al., 2015). ...
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... By assuming rational choices, policymakers commonly attribute irrational choices or attitude behaviour gaps to a lack of information or personal dispositions. However, numerous studies have evidenced that increased information, or moral appeals alone, do not necessarily translate into changes in behaviour (Dolnicar et al., 2019;Miller et al., 2010;Mont et al., 2014). Various social and psychological biases and heuristics influence people's decisions. ...
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... Unfortunately, most of the time, relying only on nudges or deliberate thinking is not quite enough [46]. This is because of the strength of habits. ...
... Unfortunately, most of the time, relying only on nudges or deliberate thinking is not quite enough [46]. This is because of the strength of habits. ...
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... Furthermore, existing research found that individuals who closely identified with Australasian Conference on Information Systems Mirbabaie et al. 2021, Sydney Digital Nudging and Sustainable Decisions representatives that support sustainable behaviour show an enhanced purchasing behaviour (Bly et al. 2015). Additionally, psychological factors such as when individuals are exposed to a mass of available information or a complex issue that requires expert knowledge that individuals do not naturally inhibit seems to impact decision-making processes (Halpern 2015;Mols et al. 2015;Mont et al. 2015). The influences described above often cause problems for individuals to translate beliefs into actions. ...
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... For example, Volpp et al. (2021) highlighted the discouraging effects of offering monetary incentives for COVID-19 vaccination, which may be associated with undesirability, unpleasantness, and unworthiness, and recommended resorting to contingent nonfinancial incentives instead. Nudge strategies have gained momentum in recent years and can be used both as a direct policy tool, wherein policymakers affect the contingencies first-hand, and indirectly, such as creating frameworks for nongovernmental organizations or other types of community services to implement nudges (Mont et al., 2014). ...
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... Furthermore, existing research found that individuals who closely identified with Australasian Conference on Information Systems Mirbabaie et al. 2021, Sydney Digital Nudging and Sustainable Decisions representatives that support sustainable behaviour show an enhanced purchasing behaviour (Bly et al. 2015). Additionally, psychological factors such as when individuals are exposed to a mass of available information or a complex issue that requires expert knowledge that individuals do not naturally inhibit seems to impact decision-making processes (Halpern 2015;Mols et al. 2015;Mont et al. 2015). The influences described above often cause problems for individuals to translate beliefs into actions. ...
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Full-text available
So-called ‘fast fashion’ consumption, amplified through cost-effective e-commerce, constitutes a major factor negatively impacting climate change. A recently noted strategy to motivate consumers to more sustainable decisions is digital nudging. This paper explores the capability of digital nudging in the context of green fashion e-commerce. To do so, digital default and social norm nudges are tested in an experimental setting of green fashion purchases. An online experiment (n = 320) was conducted, simulating an online retail scenario. Results failed to show statistically significant relationships between nudging strategies and purchase decisions. However, explorative analyses show a backfiring effect for the combination of nudges and thus, reveal a hitherto neglected impact of participants’ identification on the effectiveness of the digital nudging strategies. Consequently, this study contributes to digital nudging literature and informs practice with new insights on effective choice architectures in e-commerce.
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In this work, a two-stage traffic light detection and recognition technique based on convolutional neural networks is developed. The object detection in the first stage utilizes the information provided by the HD map. To deal with the traffic lights at different ranges, two cameras with various focal lengths are adopted. For the traffic light recognition in the second stage, the detector is combined with a classifier to distinguish different light states. It is specifically important for the identification of challenging arrow signal lights in common Taiwan road scenes. Moreover, the overall computation time is reduced by the implementation of the end-to-end network with shared feature maps. In the experiments, two public datasets (LISA and SKTL) and our own dataset collected from two routes with urban traffic scenes are used to demonstrate the effectiveness of the proposed technique.
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In recent years the concepts of 'nudge' and 'libertarian paternalism' have become popular theoretical as well as practical concepts inside as well as outside academia. But in spite of the widespread interest, confusion reigns as to what exactly is to be regarded as a nudge and how the underlying approach to behaviour change relates to libertarian paternalism. This article sets out to improve the clarity and value of the definition of nudge by reconciling it with its theoretical foundations in behavioural economics. In doing so it not only explicates the relationship between nudges and libertarian paternalism, but also clarifies how nudges relate to incentives and information, and may even be consistent with the removal of certain types of choices. In the end we are left with a revised definition of the concept of nudge that allows for consistently categorising behaviour change interventions as such and that places them relative to libertarian paternalism.
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In Nudge (2008) Richard Thaler and Cass Sunstein suggested that public policy–makers arrange decision–making contexts in ways to promote behaviour change in the interest of individual citizens as well as that of society. However, in the public sphere and Academia alike widespread discussions have appeared concerning the public acceptability of nudgebased behavioural policy. Thaler and Sunstein's own position is that the anti–nudge position is a literal non–starter, because citizens are always influenced by the decision making context anyway, and nudging is liberty preserving and acceptable if guided by Libertarian Paternalism and Rawls’ publicity principle. A persistent and central tenet in the criticism disputing the acceptability of the approach is that nudging works by manipulating citizens’ choices. In this paper, we argue that both lines of argumentation are seriously flawed. We show how the anti–nudge position is not a literal non–starter due to the responsibilities that accrue on policy–makers by the intentional intervention in citizens’ life, how nudging is not essentially liberty preserving and why the approach is not necessarily acceptable even if satisfying Rawls’ publicity principle. We then use the psychological dual process theory underlying the approach as well as an epistemic transparency criterion identified by Thaler and Sunstein themselves to show that nudging is not necessarily about “manipulation”, nor necessarily about influencing “choice”. The result is a framework identifying four types of nudges that may be used to provide a central component for more nuanced normative considerations as well as a basis for policy recommendations.
Full-text available
Ubiquitous cognitive biases hinder optimal decision making. Recent calls to assist decision makers in mitigating these biases-via interventions commonly called "nudges"-have been criticized as infringing upon individual autonomy. We tested the hypothesis that such "decisional enhancement" programs that target overt decision making-i.e., conscious, higher-order cognitive processes-would be more acceptable than similar programs that affect covert decision making- i.e., subconscious, lower-order processes. We presented respondents with vignettes in which they chose between an option that included a decisional enhancement program and a neutral option. In order to assess preferences for overt or covert decisional enhancement, we used the contrastive vignette technique in which different groups of respondents were presented with one of a pair of vignettes that targeted either conscious or subconscious processes. Other than the nature of the decisional enhancement, the vignettes were identical, allowing us to isolate the influence of the type of decisional enhancement on preferences. Overall, we found support for the hypothesis that people prefer conscious decisional enhancement. Further, respondents who perceived the influence of the program as more conscious than subconscious reported that their decisions under the program would be more "authentic". However, this relative favorability was somewhat contingent upon context. We discuss our results with respect to the implementation and ethics of decisional enhancement. © 2013. The authors license this article under the terms of the Creative Commons Attribution 3.0 License.