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When nudges aren’t enough: Norms, incentives and habit formation in public transport usage
Abstract
In a large-scale natural experiment with over 14,000 individuals, we investigate whether public transport usage can be influenced by social norms and by economic incentives. Despite their effectiveness in other domains, we find a tightly estimated zero for descriptive social norms on ridership. Increasing the economic incentive, by doubling the trial period, significantly increases uptake and long-term usage. This increase is sustained for months after removing the incentive. The effect is mainly driven by initial low users, which is evidence for habit formation and highlights the heterogeneous effects of the policy. While there is scope for long-term behavior change, norm nudges might not be the most promising approach.
... Research indicates that subconscious and emotional influences, including symbolic associations, affect transportation choices, especially in emergencies or complex decision-making scenarios (Bhattacharyya et al., 2019;Chan et al., 2024;Kinateder et al., 2014). These decisions often reflect internalized, seemingly "irrational" motives, as highlighted in the literature (Aravind et al., 2024;Avineri, 2012;Gravert and Olsson Collentine, 2021;Taylor, 2023). This calls for a more affirmative approach to travel habits than is offered by traditional psychological perspectives (Schwanen et al., 2012). ...
... Unlike traditional rational choice models, behavioral economics accounts for "irrational" motives, acknowledging that people's decisions often deviate from logic and can be shaped by their environment (Ariely, 2008;Avineri, 2012). While nudges can encourage voluntary behavioral change, research presents mixed findings regarding their effectiveness in promoting environmental consciousness and public transit use (Aravind et al., 2024;Gravert and Olsson Collentine, 2021;Hauslbauer et al., 2022). This variability indicates that the impact of nudges is complex and requires further empirical studies to fully understand their influence within the socio-material context of urban spaces (Entwistle, 2021). ...
... Research on the hidden potential of choice architecture emphasizes the importance of fostering transparency and responsible decision-making through these subtle interventions (Button, 2018;Hansen and Jespersen, 2013;Mills, 2013). Comprehensive empirical research is necessary to unravel the nuanced effects of nudging and to harness its potential for encouraging sustainable transportation behaviors (Aravind et al., 2024;Gravert and Olsson Collentine, 2021;Hauslbauer et al., 2022), Hauslbauer et al. (2022), and Gravert and Olsson Collentine (2021) has yielded conflicting results regarding the impact of nudges on promoting environmental consciousness and encouraging the use of public transit services. This inconsistency underscores the complexity of nudging mechanisms and highlights the necessity for further quantitative investigations. ...
Recent discussions on public transport as public space are particularly relevant in transit-oriented cities, where urban design profoundly shapes connectivity and pedestrian flow. Strategies such as destination consolidation, node manipulation, and privatized infrastructure, including walkways and transit systems, significantly influence these patterns. Assimilating ideas from nudge and practice theories, this study examines pedestrians' reactions to hypothetical scenarios of opening quasi-public paid areas in metro stations to the public. Using three pairs of interconnected metro stations in Hong Kong-two linked by private paid walkways (stated preference) and one by public unpaid walkways (revealed preference)-a questionnaire survey (N = 419) and discrete choice modeling were conducted. Results show adverse weather, such as rain or extreme temperatures, is a primary driver for choosing weather-protected underground paths. However, proximity and distance do not consistently predict route choice, suggesting the influence of less visible factors. For example, retail shops along a route subtly encourages usage, even for individuals with limited interest in shopping, serving as markers of convenience or familiarity. Routes with proprietary underground exits also promote underground usages. These findings reveal how deliberate design, ingrained habits and symbolic meanings collectively shape pedestrian decisions. By uncovering the social-political dynamics of pedestrian movement, this study contributes to the politics of routes discourse and offers quantitative insights for integrating micro-scale flow management in public space with broader urban planning strategies for transport infrastructure. It underscores the need to design public spaces that consider the subtle power dynamics emerging from the interplay between everyday practices and the socio-material configuration of space.
... The literature shows that Ajzen's theory of planned behavior (Ajzen, 1991) can successfully explain travel behavior, specifically carpooling for commuting (Bulteau et al., 2021). Behavioral interventions can influence individual travel behavior (Gravert and Collentine, 2021). One of the tools used in the framework of behavioral interventions is 'nudges' (Thaler and Sunstein, 2009). ...
... Despite all these reported benefits of nudges, other studies have shown them to be ineffective (Kristal and Willans, 2020) or insufficient (Gravert and Collentine, 2021). Given these limitations, it can be hypothesized that a combination of financial and non-financial incentives would effectively increase the modal shift from solo driving to sustainable mobility solutions, particularly carpooling for commuting (Bulteau et al., 2021). ...
... Kristal and Whillans (2019) showed that nudges were ineffective in shifting choices towards carpooling from home to work or to study and suggested that nudges may be ineffective in changing habitual travel behaviors. Gravert and Collentine (2021) found no successful effect of descriptive nudges on public transport choice in Sweden, and they proposed adding a strong financial incentive to increase use of public transport through the formation of travel habits. Given the divergent results of recent studies, there is a need to continue testing the impact on sustainable travel behavior of nudges in isolation and in combination with other incentives, especially financial ones. ...
Carpooling is one solution to help reduce the negative externalities of solo driving. The aim of this study is to analyze the effect of incentives on solo drivers' intention to carpool. A questionnaire survey was carried out among 1,329 participants, including 590 (38.39%) residents of the Paris metropolitan area who use a car to get to work. Modal choice estimates were modeled using multinomial logit and binomial logit econometric models for car drivers only. First, we analyzed the effect of non-financial incentives, such as nudges and trust in others during the carpooling trip. Second, we analyzed the effect of the combination of nudges with employer subsidies for sustainable mobility on the intention to carpool as a driver or passenger for the home-to-work (or home-to-school) commute. The results show that people aged 18-49, employees, and those with higher levels of education are more receptive to behavioral interventions such as nudges. Applying nudges in isolation is more effective at encouraging carpooling for commuting than combining nudges with employers' subsidies for sustainable mobility.
... An advantage of our research design is that we observe a large share of individual transport mode choices, including public transportation, car sharing, rental cars, and ride-hailing and ride-sharing services. This allows us to study substitution between different modes of transport and sets our paper apart from previous research in this domain which mostly used data on a single transport mode only (see, e.g., Kormos et al., 2014;Kristal and Whillans, 2020;Gravert and Collentine, 2021). In contrast to previous studies observing transportation behavior across multiple transport modes (Cellina et al., 2019;Hintermann et al., 2024;Götz et al., 2023), participants in our study were not aware that they were participating in a field experiment. ...
... The available experimental evidence is mostly based on self-reported (stated) choice data gathered via surveys or lab experiments (e.g., Avineri and Waygood, 2013;Filippini et al., 2021;Piras et al., 2021;Bao and Lim, 2022). Rare exceptions are Cellina et al. (2019), Gravert and Collentine (2021), Kristal and Whillans (2020) and Götz et al. (2023) who analyze real-world transportation behavior (revealed preferences). We contribute to filling this gap by running a field experiment at a large German company where we are able to track employees' mode choice and spending within a mobility budget. ...
... Social comparisons, the most frequently evaluated type of ''green nudge'', have proven effective at reinforcing pro-environmental behavior (Farrow et al., 2017), particularly in the area of energy and water conservation by households (e.g., Schultz et al., 2007;Nolan et al., 2008;Ferraro et al., 2011;Ferraro and Price, 2013;Allcott and Rogers, 2014;Allcott and Kessler, 2019;Andor et al., 2020b;Brick et al., 2023). In transportation research, social comparisons have been found to reduce (self-reported) car usage (Kormos et al., 2014), while having no effects on decisions to car-pool (Kristal and Whillans, 2020) or use public transit (Gravert and Collentine, 2021). In view of the weak performance of nudges in the transportation context, Gravert and Collentine (2021) conjecture that ''switching transport options comes at a higher effort and even monetary cost'' compared to other environmental domains. ...
... An advantage of our research design is that we observe a large share of individual transport mode choices, including public transportation, car sharing, rental cars, and ride-hailing and ride-sharing services. This allows us to study substitution between different modes of transport and sets our paper apart from previous research in this domain which mostly used data on a single transport mode only (see, e.g., Kormos et al., 2014;Kristal and Whillans, 2020;Gravert and Collentine, 2021). In contrast to previous studies observing transportation behavior across multiple transport modes (Cellina et al., 2019;Hintermann et al., 2024;Götz et al., 2023), participants in our study were not aware that they were participating in a field experiment. ...
... The available experimental evidence is mostly based on self-reported (stated) choice data gathered via surveys or lab experiments (e.g., Avineri and Waygood, 2013;Filippini et al., 2021;Piras et al., 2021;Bao and Lim, 2022). Rare exceptions are Cellina et al. (2019), Gravert and Collentine (2021), Kristal and Whillans (2020) and Götz et al. (2023) who analyze real-world transportation behavior (revealed preferences). We contribute to filling this gap by running a field experiment at a large German company where we are able to track employees' mode choice and spending within a mobility budget. ...
... Social comparisons, the most frequently evaluated type of ''green nudge'', have proven effective at reinforcing pro-environmental behavior (Farrow et al., 2017), particularly in the area of energy and water conservation by households (e.g., Schultz et al., 2007;Nolan et al., 2008;Ferraro et al., 2011;Ferraro and Price, 2013;Allcott and Rogers, 2014;Allcott and Kessler, 2019;Andor et al., 2020b;Brick et al., 2023). In transportation research, social comparisons have been found to reduce (self-reported) car usage (Kormos et al., 2014), while having no effects on decisions to car-pool (Kristal and Whillans, 2020) or use public transit (Gravert and Collentine, 2021). In view of the weak performance of nudges in the transportation context, Gravert and Collentine (2021) conjecture that ''switching transport options comes at a higher effort and even monetary cost'' compared to other environmental domains. ...
... Regarding public transportation, Gravert and Collentine (2021) show in a large-scale study in Sweden that economic incentives in the form of free trial periods can have lasting effects through habit formation. ...
... Communication In the same study, however, Gravert and Collentine (2021) also show that the mere provision of informational nudges is less likely to be effective. Such "suasoric" measures, which rely on invoking social expectations (descriptive norms) or moral arguments (injunctive norms) to influence behavior, are characterized by their low-threshold nature and cost efficiency. ...
We investigate the impact of a gamified experiment designed to promote sustainable mobility among students and staff members of a Swiss higher-education institution. Despite transportation being a major contributor to domestic CO2 emissions, achieving behavioral change remains challenging. In our two-month mobility competition, structured as a randomized controlled trial with a 3x3 factorial design, neither monetary incentives nor norm-based nudging significantly influences mobility behavior. Our (null) results suggest that there is no "gamified quick fix" for making mobility substantially more sustainable. Also, we provide some lessons learned on how not to incentivize sustainable mobility by addressing potential shortcomings of our mobility competition.
... Studies also show that workplace initiatives can also create positive behavioral spillover effects across contexts, where employees also report undertaking conservation behaviors at home (111). However, for habitual behaviors such as employee commuting, nudges have often proved ineffective (112,113). This is unsurprising, because such travel habits often are determined by infrastructure availability, cost, and city design in addition to behavioral factors (113,114). ...
... However, for habitual behaviors such as employee commuting, nudges have often proved ineffective (112,113). This is unsurprising, because such travel habits often are determined by infrastructure availability, cost, and city design in addition to behavioral factors (113,114). ...
Conservation of biodiversity is above all else an exercise in human persuasion. Human behavior drives all substantive threats to biodiversity; therefore, influencing it is the only path to mitigating the current extinction crisis. We review the literature across three different axes to highlight current evidence on influencing human behavior for conservation. First, we look at behavioral interventions to mitigate different threats, from pollution and climate change to invasive species and human disturbance. Next, we examine interventions focused on different stakeholders, from voters, investors, and environmental managers to consumers, producers, and extractors. Finally, we review delivery channels, ranging from mass and social media to interventions involving changes to the physical environment or carried out in person. We highlight key gaps, including the lack of scale and robust impact evaluation of most interventions, and the need to prioritize behaviors, overcome the reproducibility crisis, and deal with inequality when designing and implementing behavior change interventions.
... Previous approaches have heavily relied on incentives and appeals targeting people's extrinsic motivation including economic incentives directly rewarding sustainable behaviour or more abstract rewards such as social recognition. However, extrinsically motivated interventions have often failed to achieve long-lasting behaviour change (Frey and Rogers, 2014;Kaiser et al., 2020;Gravert and Olsson, 2021). It has therefore been argued that for pro-environmental behaviour (PEB) to be sustained in the long run, it needs to be internalised and thus motivated by intrinsic factors (Steinhorst and Klöckner, 2017). ...
... Second, research has stressed the potential for positive emotions (specifically warm glow) to form a positive feedback loop with climate change engagement (Van Der Linden, 2018;Brosch and Steg, 2021;Schneider and van der Linden, 2023) and we are among the first studies to empirically explore whether appealing to intrinsic motives can kick-start such a self-reinforcing 'virtuous cycle'. At the same time, our longitudinal design allows us to explore the persistence of treatment effects, at least in the short-term (Allcott and Rogers, 2014;Bernedo et al., 2014;Brandon et al., 2017;Hume et al., 2020;Gravert and Olsson, 2021). In this respect, we also address the challenge of whether warm glow experiences can be exogenously manipulated in a controlled experimental setting (Hartmann et al., 2017). ...
We conducted a large-scale online experiment to examine whether climate change messaging can induce emotions and motivate pro-environmental action. We study how exposure to explicit positive (‘warm glow’) and negative (‘cold prickle’) emotional appeals as well as a traditional social norm communication affects pro-environmental action. We find that a simple call to take action to mitigate climate change is at least as affective as social norm message framing and emotional appeals. Our results highlight the difficulty of designing messaging interventions that effectively harness emotional incentives to promote pro-environmental action. Messages that explicitly emphasise the personal emotional benefits of contributing to environmental causes or the adverse emotional effects of not doing so seem to fall short of motivating pro-environmental effort. Our findings underscore the need for caution when incorporating emotive appeals into policy interventions.
... The intervention also provides people with objects (cards and whistles) that remind them of the intervention, but more importantly, that allow them to provide and receive "feedback" to and from others in a relatively safe, playful way. Apart from reducing resistance to the intervention by playing on gentleness and humor rather than enforcement and authority, this also supports a sense of self-and group-efficacy [73,74], which are both essential to drive collective change and should ideally strengthen the capacity of groups and individuals to collectively adapt to changing conditions and new challenges. ...
... However, such approaches falter for large-scale socially complex problems, such as traffic norms or domestic violence, and do not address multiple influences on behavior. This is perhaps why nudge-based approaches commonly fail for sustainable behavior change [74,75,77]. ...
Achieving more equitable, safer, and resilient societies—crucial dimensions of social sustainability—depends on durable transformations in people’s behavior. Traditional policy interventions attempt to influence people’s behavior in different ways, such as increased policing, fines, or awareness campaigns, but often have limited effects because they fail to systematically address local determinants of behavior. In this paper, we analyze two complex behavioral policy interventions to illustrate how installation theory can provide a framework to systematically analyze and design for large-scale behavioral change to support social sustainability. We focus on two of Antanas Mockus’ iconic “civic culture” interventions to reduce deaths in traffic accidents and domestic violence in Colombia. To study them, we collected intervention reports, citizens’ narratives, creators’ accounts and press articles to identify their main characteristics and behavioral techniques. In our results, we find that the civic culture approach used in these two interventions addresses physical, psychological and social determinants of behavior in ways that reduce reactance and promote mutual regulation and collective agency. By unraveling the essential factors of behavioral influence, installation theory and related frameworks provide a useful guide to structure, analyze and report interventions that address the behavioral components of social sustainability.
... There is a long strand of literature on how to reduce car use and promote sustainable mobility, in particular public transport. Studies range from behavioral economic studies (such as Gravert andCollentine, 2021, Kristal andWhillans, 2020) to regulatory requirements (such as low emission zones, Tarriño-Ortiz et al., 2022) to extensive research on optimal policy design (Hörcher and Tirachini, 2021). The latter discusses, among other things, the pricing of public transport, public space, and the street. ...
... There is now a large experimental literature that examines whether people behave in a more environmentally friendly way when they are informed about the behavior of other people. These studies measure the behavioral adjustments brought about by providing information about other people's energy conservation (Schultz et al. 2007; Allcott 2011; Allcott and Rogers 2014), residential water usage (Ferraro, Miranda and Price 2011), towel reuse (Reese, Loew and Steffgen 2014), recycling or littering behavior (Reiter and Samuel 1980;Cialdini, Reno and Kallgren 1990;Schultz 1999), use of public transport (Gravert and Collentine 2021), or food choice (Sparkman and Walton 2017;Griesoph et al. 2021;Dannenberg, Klatt and Weingärtner 2024). The results show that subjects tend to adapt their behavior to the social norm and behave in a more environmentally friendly way when others do the same. ...
As the international community grapples with the complex challenge of climate change, policymakers need reliable data and information to develop effective strategies for reducing greenhouse gas emissions in the business and household sectors. Experimental economics offers a valuable tool for studying human behavior and economic decision-making under controlled conditions and for deriving insights for effective and socially acceptable policy measures. This paper presents contributions from experimental economics to the design and evaluation of climate policy to illustrate important insights and methodological advances.
... With specialisation in identical nudges, e.g. high-priority task specialisation, individuals might learn that the stimulus is neither rewarding nor relevant (Toates, 1997;Sugden, 2009;Gravert and Olsson Collentine, 2021). ...
Purpose
The use of digital platforms is continuously increasing. This naturally entails various risks and opportunities. However, these risks and opportunities have not yet been studied in the context of team familiarity and task prioritisation. Therefore, this paper evaluates how team familiarity and task prioritisation affect both task-acceptance and task-processing time within a digital platform utilising a broadcast mechanism in a logistical context. Hence, our findings contribute to a deeper understanding of the relationship between digital platforms and intra-organisational team dynamics.
Design/methodology/approach
This study investigated a real-world observational dataset from an intra-organisational digital work platform utilised to organise shunting tasks in yard management. We tested our hypotheses by applying a linear mixed-effects model to our dataset encompassing 146,446 yard transport missions completed between January 2022 and April 2023.
Findings
Our study shows that high levels of team familiarity were associated with shorter task-processing times on a digital platform with a broadcast mechanism as explained by the transactive memory system theory. For task prioritisation, higher same-month high-priority task specialisation also resulted in shorter task-processing times, which is supported by the self-determination and social loafing theories. Same-month high-priority task specialization refers to the drivers on the yard who have repeatedly executed tasks with the same high priority within a month. Conversely, higher team familiarity levels led to longer task-acceptance times, based on the learning curve and nudge theories. Similarly, higher same-day high-priority task specialisation correlated with longer task-acceptance times due to the habitual effect.
Originality/value
First, our research contributes to the limited research in the field of yard management through its empirical investigation of social interaction and real-world operational-level processes for driver teams focused on shunting transport. Second, prior research in the context of digital platforms has focused on the individual level, while our research is dedicated to the team level, which highlights the communication and social interaction of drivers with other operators in the warehouse. Third, we discuss the relationship between social interaction and informal communication along with their implications for the success of digital platforms.
... Therefore, scholars stated that once if an individual experiences the positive aspects of the changed lifestyle, this motivates them to continue even without any extrinsic motivation (Gneezy et al., 2011). Furthermore, Gravert and Collentine (2021) empirically showed that incentives positively impacted habit with respect to the use of public transport. With respect to the use of technology, incentives might lead the formation habit (Kilani et al., 2023). ...
Purpose
This study aims to identify the significant factors that influence the continuation intention (CI) to use a digital wallet in the regions with low technology infrastructure and among the consumers possessing low levels of digital and financial literacy.
Design/methodology/approach
Data for the study were collected from the rural parts of South India with 295 digital wallet users. Co-variance-based structural equation modelling (SEM) (CB-SEM) using maximum likelihood estimation method and Bayesian SEM (BSEM) approaches were executed to test the influence of independent variables on the dependent variable and to ensure the validation of the proposed hypothetical model.
Findings
The results showed that trust, incentives, technology satisfaction (TS), facilitating condition, performance expectancy, effort expectancy, habit and hedonic motivation significantly influenced the CI to use a digital wallet. In addition, incentives positively impact habit for the CI to use a digital wallet.
Research limitations/implications
The present study is based on the samples from the regions with low technology infrastructure and among the consumers possessing low levels of digital and financial literacy in the rural parts of South India, which limits the generalisation of results.
Practical implications
The results provide impetus to the government, digital wallet marketers and users regarding how the CI to use a digital wallet can be encouraged among the low-adoption regions.
Originality/value
This study remains unique as the assessment of CI to use a digital wallet was conducted in low-adoption regions (rural parts of India) in extending Unified theory of acceptance and use of technology 2 with TS. A comparison of results arrived from CB-SEM with those of the BSEM ensures that the validation of the hypothetical model is found to be another major methodological contribution towards the consumer behaviour literature.
... Within the context of transport, data in these studies often measure public transport or car use, as these are easier to observe than walking or cycling. Recent examples of randomized experiments include Gravert and Olsson Collentine (2021) on the efect of social comparisons on public transport use, Lieberoth et al. (2018) on the efect of health information on public transport use, Kristal and Whillans (2020) on the efect of diferent information interventions on car use and Gessner et al. (2023) and Goetz et al. (2023) on the efect of social comparisons and moral appeals on mode choice. A general fnding in this literature is that nudges are not efective in changing transportation habits. ...
The negative health impacts of passive transport can be substantial both from the individual point of view and with respect to public spending on health. We run a field-experiment to study the effectiveness of information in encouraging active transport choices. The treatment is carried out using a smartphone application that automatically tracks users' daily transport choices. We find that the treatment group receives and internalizes the information, but we do not find a statistically significant effect on their travel behavior.
... Segregated cycle lanes and clearly painted cycle paths are an important determinant of bicycle usage (Doğru et al., 2021). Adequate provision, rather than just information, is crucial for encouraging habitual alternative transport usage (Neoh et al., 2017;Kristal and Whillians, 2020;Gravert and Collentine, 2021). ...
Behavioural science has sought to promote pro-environmental behaviours including climate-friendly dietary change, and to reduce travel emissions and excessive wastes. Nevertheless, there is a debate about how effective behavioural interventions are, and in turn, about the real barriers to enduring pro-environmental behaviour change. In this context, we conceptualise brown sludge as multi-level impediment to pro-environmental behaviour change, which results in higher environmental costs shared by the broader society, rather than solely by the individual actor. We propose that brown sludge comprises an array of additional transaction costs, encompassing, but not restricted to, psychological, temporal, and uncertainty costs. Brown sludge can occur at the individual, social, institutional, and societal levels. Examples include confusing eco-information, delay and disinformation campaigns, and complicated systems and infrastructure leading to carbon lock-in.
... The findings for social descriptive norms are mixed; some studies find no effect (Einhorn 2020;Griesoph et al. 2021), whereas others show that specific ways of framing the descriptive norm can foster sustainable choices, even when the norm is described as something that only a minority of people practice (Demarque et al. 2015;Sparkman and Walton 2017). Informing newcomers who have recently moved to a new neighborhood about the use of public transport by locals does not have much effect (Gravert and Olsson Collentine 2021). Existing studies on sustainable clothing are largely based on self-reported consumption decisions or do not inform participants of others' norms, which is why they are not listed in table 2 (Hustvedt and Bernard 2010;Kumar, Manrai, and Manrai 2017;Lin and Niu 2018;Kim and Seock 2019;Lo, Tsarenko, and Tojib 2019;Park and Lin 2020). ...
... The most prominent example of such an attempt is the use of so-called home energy reports (Allcott 2011), but similar interventions have been evaluated for water use (Brent et al. 2020;Ferraro and Price 2013;Torres and Carlsson 2018), non-residential energy use (Klege et al. 2022), food waste (Kallbekken and Saelen 2013), and household waste (Ek and Söderberg 2021). At the same time, there is evidence that the effect of information on behavior decreases over time (Ferraro et al. 2011), and there are examples of zero effects in some settings (e.g., Gravert and Collentine 2021). ...
We provide the first estimates of how pro-environmental consumers reduce their total carbon footprint using a carbon calculator that covers all financial transactions. We use data from Swedish users of a carbon calculator that includes weekly estimates of users’ consumption-based carbon-equivalent emissions based on detailed financial statements, official registers, and self-reported lifestyle factors. The calculator is designed to induce behavioral change and gives users detailed information about their footprint. By using a robust difference-in-differences analysis with staggered adoption of the calculator, we estimate that users decrease their carbon footprint by around 10% in the first few weeks, but over the next few weeks, the reduction fades. Further analysis suggests that the carbon footprint reduction is driven by a combination of a shift from high- to low-emitting consumption categories and a temporary decrease in overall spending, and not by changes in any specific consumption category.
... There is a long strand of literature on how to reduce car use and promote sustainable mobility, in particular public transport. Studies range from behavioral economic studies (such as Gravert andCollentine, 2021, Kristal andWhillans, 2020) to regulatory requirements (such as low emission zones, Tarriño-Ortiz et al., 2022) to extensive research on optimal policy design (Hörcher and Tirachini, 2021). The latter discusses, among other things, the pricing of public transport, public space, and the street. ...
... Plus qu'une démonstration de la pertinence (ou non) des nudges pour réorienter les comportements de mobilité vers des choix plus durables, la mise en balance de l'ensemble de ces travaux doit avant tout nous inviter à modérer les attentes des autorités publiques sur le pouvoir d'action de cet outil et à envisager l'éventualité qu'il existe des options parfois plus prometteuses (Gravert et Collentine, 2021). Sur les plans politique et opérationnel, enfin, l'objectif était de permettre des avancées dans l'aide à la décision, l'accompagnement des décideurs publics, et la mise en place de mesures mieux adaptées et davantage performantes (car comptables des spécificités des territoires et de leurs habitants). ...
Les nudges appliqués à la mobilité des individus alimentent un nombre croissant d’expérimentations de terrain. Le présent article présente le concept de nudge, puis propose un état de l’art de la bibliographie et une classification des principaux biais cognitifs sur lesquels les nudges s’appuient pour modifier une architecture de choix. La deuxième partie de l’article présente les conflits de rationalités et la négociation qui en résulte dans le fil de la conception d’un jeu de nudges dédié aux changements de comportements en termes de mobilité, jeu destiné à s’insérer dans une application de téléphone multifonctions.Au-delà des approches définitionnelles et de la production de nudges originaux, ce qui importe ici est de distinguer, en théorie et en pratique, les divers leviers à partir desquels une incitation peut se mettre en place, et comment les technologies de l’information et de la communication (TIC) peuvent être mobilisées pour tenter d’influer sur les comportements. Articulant les perspectives de l’économie comportementale, des sciences de l’information et de la communication et des sciences cognitives, la recherche s’inscrit dans une analyse technopolitique de fond.
... In addition, changing mobility behavior toward more sustainable options, such as public transportation, is a complex societal challenge (e.g., Gravert & Collentine, 2021;Hauslbauer et al., 2022;Steg, 2005). Moreover, former studies often showed mixed results regarding the effects of digital nudging to increase the use of more sustainable mobility forms, such as public transportation (Cellina et al., 2019). ...
The urgency of global climate change is becoming increasingly evident, but prevailing mobility patterns in developed countries still cause severe environmental damage. Therefore, developed countries need to change their mobility patterns fundamentally, such as modal changes to public transportation instead of private car use. Digital nudging in digital mobility applications is a novel and promising way to influence modal changes to public transportation. In this study, we conduct an online experiment with 183 participants who are being nudged toward public transportation trip options. Our results show that combining two different digital nudges significantly affects the choice of public transportation options. By contrast, single nudges do not significantly change the choice of public transportation trips. With our findings, we contribute to the research stream of digital nudging and the transportation literature and provide insights for practice to address the adverse effects of current mobility patterns.
... Although digital nudging is a promising approach to inducing behavioural changes in the mobility context, changing mobility behaviour towards more sustainable options, such as public transportation, is still a complex societal challenge (e.g. Gravert & Collentine, 2021;Hauslbauer et al., 2022;Steg, 2005), and little is known about whether and how digital nudging supports behavioural changes (Henkel & Kranz, 2018). First studies analysed in a randomised controlled trial how digital nudges in a mobility app can support modal changes, e.g. from private car use to public transport use. ...
The urgency of climate change is evident worldwide, but current mobility patterns still cause severe environmental damage. The largest share of these mobility-related problems is caused by everyday private car use, such as commuting. One way to change mobility patterns is through digital nudging in the form of trip recommendations to increase commuters' public transportation use. To examine the effects of the recommendations, we undertake a choice-based conjoint analysis and determine whether participants choose the recommended trip option more frequently and whether the recommendations influence participants' public transportation preferences. Our results show differences based on com-muters' travel times and mobility app use. Significant positive effects were observed among commuters with a short travel time who do not usually use mobility apps. This study contributes to the digital nudging and transportation literature, and has practical implications in terms of using recommendations to encourage switching from private cars to public transportation. ARTICLE HISTORY
... Les gestionnaires de gares insistent surtout sur le port du masque, lequel fait l'objet d'annonces audio régulières et d'affichettes nombreuses, de 2020 à 2022 inclus. Est-ce le constat de leur faible capacité à influencer la conduite des passagers qui explique le retrait progressif des nudges (ce qui corrobore d'ailleurs une vaste littérature sur le faible succès de leur emploi dans les systèmes de transport (Te Brömmelstroet, 2014 ;Sunstein, 2017 ;Gravert et Collentine, 2021), ou leur maintien est-il lié à d'autres avantages qu'ils procurent ? On note par exemple qu'ils restent apposés à l'abord des sandwicheries pour indiquer tout simplement le sens de la queue, ils sont donc en quelque sorte maintenus pour des raisons de gestion commerciale plutôt que sanitaires. ...
Since the pandemy, the carrying capacity of major railway stations has been restricted to respect the distance. In Asian metropolises, a tech-driven flow management system reinforces the surveillance of travellers and help the maintenance of a top affluence in station’s buildings. In France, an attempt is made to space out travelers with less intrusive processes, such as signage and boarding protocol adaptation. A comparison between these two responses leads us to question what physical distancing does, here and there, to the practices and places of transit and to the economic injonction to densify flows in and around stations until now. Articulating the approaches of crowding science and health regulation in transit environments, the article presents a transcontinental comparison, and then questions the status of major station as post pandemic urbanism showroom.
Recent reports have highlighted the importance of changing human behavior if climate change is to be mitigated. In this respect, behaviorally informed interventions are considered promising tools. In particular, these interventions could be applied in the transport sector, where the mitigation potential is high. However, a comprehensive synthesis of the evidence on behaviorally informed interventions in this field is lacking, although such syntheses are extremely useful for researchers, policymakers, and funding bodies alike. This study addresses this gap by presenting a systematic map of behaviorally informed interventions that target sustainable mobility decisions. An extensive review of more than 30,000 articles revealed a substantial corpus of 204 relevant studies. While studies on usage behavior (e.g. fuel-efficient driving) and studies addressing the private context are most prevalent, the synthesis highlights that existing studies investigated a remarkably diverse set of heterogeneous mobility decisions. Additionally, studies addressing the professional context or positioned at the intersection of the private and professional sphere were identified, highlighting the potential for behavior change interventions in multiple contexts. This study provides a foundational resource for understanding the scope of existing research and uncovering underexplored areas with high mitigation potential. The findings not only inform future academic research but also guide policymakers and practitioners in designing effective, behaviorally informed strategies to reduce transportation's environmental impact.
This study used randomised controlled trials to test the effectiveness of three behavioural interventions, i.e., focalism, social norm, and visualisation, in changing people’s housing and commuting preferences. The experiment was conducted online via Credamo, one of the largest online panel data providers in China. It included only renters who needed to commute in the city of Xi’an, China, as participants in the study. The results show that behavioural interventions significantly increased respondents’ willingness to adopt more sustainable commute modes, such as walking or cycling, and reduced the tendency to use private cars. Among the three behavioural interventions, the social norm intervention had the largest and most significant impact. The findings shed light on the potential of applying behavioural interventions in sustainable urban transport management. More importantly, the results demonstrate the possibility of using behavioural interventions to incorporate sustainable urban development goals into housing decisions.
In previous studies, many travel-behavior-change strategies often relied on single behavior determinants or psychological theories, overlooking the incorporation of sociopsychological theories for guidance in their design. Integrating these theories could offer consistent guidance for program developers and enhance intervention effectiveness. This paper systematically reviews interventions targeting travel-behavior change, with a focus on self-determination theory and its principles of satisfying individuals’ competence, autonomy, and relatedness needs for enacting change. Additionally, experiment design methods, including randomized controlled trials and quasi-experimental designs, are reviewed and discussed. Key findings highlight the effectiveness of personalized interventions and integrating feedback with goal-setting strategies. Given the limited direct references to sociopsychological theories in existing studies, we explore relevant sociopsychological theories applicable to travel-behavior-change programs to provide examples of how strategies could be designed based on them. This review contributes valuable insights into the development of strategies for changing travel behavior, offering a theoretical framework for researchers and practitioners to guide intervention design, experimentation, and evaluation. Leveraging these theories not only facilitates reproducibility but also provides a standardized approach for transportation demand management program developers.
Mobile applications hold promise to foster sustainable mobility behavior, but evaluations of their effectiveness are subject to a number of empirical challenges. We conduct a randomized controlled trial with three distinctive features: unobtrusive tracking of the control group, limited sample attrition, and a representative sample. In our study, 410 participants track their mobility behavior over a 5 week period. After 1 week, the treatment group engages with the user interface of the “Swiss Climate Challenge App”. The user interface combines information on individual CO 2 emissions with gamification features. We find a treatment effect that implies a 9.8 % reduction in emissions caused by access to the mobile application. While we lack the statistical power to exclude a zero average effect, we find statistically significant emission reductions in the second half of the intervention period, among subjects in medium population density areas, and among men. Our findings suggest that mobile applications could generate considerable net benefits, but larger studies will be needed for validation.
Nudges are approaches that direct individuals to perform particular courses of action to meet a pre-determined goal, without coercion. Previous literature has explored the design of nudge and its impact on users’ behavior in several domains and contexts. Still, scarce and fragmented knowledge about the design approaches, ethical considerations, and theoretical grounds have been presented by previous literature. Hence, this study aims to investigate the literature through bibliometric analysis and a narrative review of the nudging techniques and their impact on social behavior with an emphasis on the application domains, nudge designs, ethical considerations, and theoretical grounds. Focusing on nudge design and impact, we scan the landscape of the research in the area through bibliometric analysis and narrative review approaches. We searched for papers that included keywords related to nudges from the Scopus database and analyzed them using a bibliometric-based approach. Several diagrams that visualize the terms of the studies, sources, citations, and thematic trends were presented. The research provides several insights for researchers in terms of the design of the nudge, the theoretical grounds, ethical considerations, and the application domains of nudging.
Understanding how people choose routes in urban environments is essential for effective urban planning. While conventional transportation studies focus on utilitarian decision-making, this research investigates the complex interplay between human-environment interactions and emotional attachments to places, which influence transportation choices. Specifically, we examine the impact of sense of place in pedestrian route choice within a densely populated urban university community. Unlike typical urban settings characterized by clear roads and landmarks, university environments often feature intricate layouts with diffuse pathways, shared spaces, and a lack of clear spatial hierarchies. This complexity challenges conventional spatial knowledge acquisition methods. Individuals navigating such environments tend to rely on socio-sensory wayfinding strategies, developing emotional connections to specific places and routes over time. Consequently, route choices in these contexts may not always be deliberate but rather subconscious and nuanced. Our study focuses on elucidating the impact of the sense of place—a composite of conscious and subconscious perceptions, emotions, and attachments to a location—on daily route decisions. Through structural equation modeling (SEM) analysis, we demonstrate that the sense of place significantly influences route choices within community building complexes, surpassing utilitarian considerations as a primary explanatory factor. These findings underscore the importance of emotional and psychological factors in shaping urban route decisions, offering valuable insights for urban planning and management strategies.
Financial incentives are widely used to get people to adopt desirable behaviors. Many small landholders in developing countries, for example, receive multiyear payments to engage in conservation behaviors, and the hope is that they will continue to engage in these behaviors after the program ends. Although effective in the short term, financial incentives rarely lead to long-term behavior change because program participants tend to revert to their initial behaviors soon after the payments stop. In this article, we propose that four psychological constructs can be leveraged to increase the long-term effectiveness of financial-incentive programs: motivation, habit formation, social norms, and recursive processes. We review successful and unsuccessful behavior-change initiatives involving financial incentives in several domains: public health, education, sustainability, and conservation. We make concrete recommendations on how to implement the four above-mentioned constructs in field settings. Finally, we identify unresolved issues that future research might want to address to advance knowledge, promote theory development, and understand the psychological mechanisms that can be used to improve the effectiveness of incentive programs in the real world.
Advancing transformative change for sustainability requires population‐wide behavior change. Yet, many behavioral interventions tackling environmental problems only examine average effects on the aggregate, overlooking the heterogeneous effects in a population. We developed and preregistered a novel audience segmentation approach to test the diverse impact of conservation messaging on reducing demand for exotic pets (private action ‐ i.e., desire to own exotic pets or visit wildlife entertainment places) and fostering citizen engagement for system‐wide change (civic action ‐ e.g., signing a petition or participating in a protest against the exotic pet trade). Through an online survey with US participants (n = 2953), we identified 4 population segments (early adopters, early majority, late majority, and laggards), representing varying levels of commitment to wildlife conservation and then randomly assigned each segment to one of 3 messaging conditions. Messages highlighting negative consequences of the exotic pet trade and the power of collective action for system change effectively promoted private action among all segments except early adopters (ηp² = 0.005). Among civic actions, only the collective action message motivated early adopters and the early majority to sign petitions (φC = 0.193 and φC = 0.097, respectively). Furthermore, the 4 segments showed distinct reasoning for action and inaction on wildlife conservation, with certain relational values, such as care, serving as both motivations and barriers to action. These findings highlight the need for targeted behavioral interventions across diverse populations.
Humanity has a shrinking window to drastically reduce greenhouse gas emissions, yet climate action is still lacking on both individual and policy levels. We argue that this is because behavioral interventions have largely neglected the basic principles of operant conditioning as one set of tools to promote collective climate action. In this perspective, we propose an operant conditioning framework that uses rewards and punishments to shape transportation, food, waste, housing, and civic actions. This framework highlights the value of reinforcement in encouraging the switch to low-emission behavior, while also considering the benefit of decreasing high-emission behavior to expedite the transition. This approach also helps explain positive and negative spillovers from behavioral interventions. This paper provides a recipe to design individual-level and system-level interventions to generate and sustain low-emission behavior to help achieve net zero emissions.
This paper reports results from a randomized control trial with a pay-as-you-go (PAYG) solar system provider in Pakistan. In the default treatment, customers are told the amount to pay every month to keep the system active. In a first treatment, customers are assisted in planning this monthly payment. A second treatment discloses that payments can be made flexibly within the month. This disclosure may reduce contract cancellation by helping minimize transaction costs but may increase contract complexity and reduce discipline. A third treatment combines flexibility with assistance in planning payments. Disclosing flexibility increases contract cancellation relative to the default, but combining flexibility with planning offsets this effect. Treatment effects appear stronger among users facing high mental constraints and transaction costs. These findings support the idea that behavioral factors, such as inattention and commitment problems, lay behind the negative impact of flexibility on cancellation. The results suggest that providers of PAYG systems may face a trade-off between disclosing complex contractual features and customer retention. Planning helps customers handle the added complexity.
In the literature on behavior change it has commonly been assumed that sustained changes in behavior means that habits have been formed and that sustained behavior change is achieved through the formation of habits. In this paper we argue that habit formation is often confused with a variety of alternative mechanisms through which sustained changes in behavior can be achieved. These include: learning, information acquisition, status quo bias, taste discovery, technology, commitment devices, social influences, and concomitant changes to choice environments. Understanding these mechanisms is important for determining why specific interventions work or don’t work and for aiding in the design of more effective mechanisms for inducing sustained behavior change.
Across five field experiments with employees of a large organization (n = 68,915), we examined whether standard behavioural interventions (‘nudges’) successfully reduced single-occupancy vehicle commutes. In Studies 1 and 2, we sent letters and emails with nudges designed to increase carpooling. These interventions failed to increase carpool sign-up or usage. In Studies 3a and 4, we examined the efficacy of other well-established behavioural interventions: non-cash incentives and personalized travel plans. Again, we found no positive effect of these interventions. Across studies, effect sizes ranged from Cohen’s d = −0.01 to d = 0.05. Equivalence testing, using study-specific smallest effect sizes of interest, revealed that the treatment effects observed in four out of five of our experiments were statistically equivalent to zero (P < 0.04). The failure of these well-powered experiments designed to nudge commuting behaviour highlights both the difficulty of changing commuter behaviour and the importance of publishing null results to build cumulative knowledge about how to encourage sustainable travel. Kristal and Whillans conducted five field experiments (n = 68,915) designed to increase sustainable commuting using standard behavioural science tools. The interventions’ failures highlight the difficulty of changing commuter behaviour using this approach.
Nudges are popular types of interventions. Recent years have seen the rise of ‘norm-nudges’—nudges whose mechanism of action relies on social norms, eliciting or changing social expectations. Norm-nudges can be powerful interventions, but they can easily fail to be effective and can even backfire unless they are designed with care. We highlight important considerations when designing norm-nudges and discuss a general model of social behavior based on social expectations and conditional preferences. We present the results of several experiments wherein norm-nudging can backfire, and ways to avoid those negative outcomes.
Governments are increasingly adopting behavioral science techniques for changing individual behavior in pursuit of policy objectives. The types of “nudge” interventions that governments are now adopting alter people’s decisions without coercion or significant changes to economic incentives. We calculated ratios of impact to cost for nudge interventions and for traditional policy tools, such as tax incentives and other financial inducements, and we found that nudge interventions often compare favorably with traditional interventions. We conclude that nudging is a valuable approach that should be used more often in conjunction with traditional policies, but more calculations are needed to determine the relative effectiveness of nudging.
Personal travel planning (PTP) is generally regarded as an effective approach to voluntary travel behavior change in the domain of transportation research. However, this view has recently been challenged by findings from another research domain, public health research, reporting little or no effect of PTP-based interventions. We argue that these conflicting results regarding the effectiveness of PTP-based measures are due to different understandings of which research designs should be used: Transportation research tends to be based on large-scale quasi-experimental designs whereas public health research tends to favor experimental designs such as randomized control trials (RCTs). Consequently, we argue, the discrepancy may at least partly be resolved by a more nuanced position on what empirical evidence really matters when evaluating if an intervention is effective or not. In the empirical part of the paper, we meta-analytically re-analyze ten quasi-experimental PTP evaluation studies and report an experimental RCT-based study testing the effectiveness of a PTP strategy implemented in a major German city. Including all information in one meta-analytical synthesis yields a standardized effect size estimate of Cohen's h = 0.12, documenting a small but reliable effect of PTP interventions. When implementing a PTP like one of those analyzed in this paper, in other words, we can expect an average reduction of the car modal split share of about 5 percentage points. We close by discussing the implications of our results for future PTP evaluation studies and the dispute about what kind of empirical evidence really matters when evaluating the effectiveness of PTP measures.
Inattention and imperfect information bias behavior toward the salient and immediately visible. This distortion creates costs for individuals, the organizations in which they work, and society at large. We show that an effective way to overcome this bias is by making the implications of one’s behavior salient in real time, while individuals can directly adapt. In a large-scale field experiment, we gave participants real-time feedback on the resource consumption of a daily, energy-intensive activity (showering). We find that real-time feedback reduced resource consumption for the target behavior by 22%. At the household level, this led to much larger conservation gains in absolute terms than conventional policy interventions that provide aggregate feedback on resource use. High baseline users displayed a larger conservation effect, in line with the notion that real-time feedback helps eliminate “slack” in resource use. The approach is cost effective, is technically applicable to the vast majority of households, and generated savings of 1.2 kWh per day and household, which exceeds the average energy use for lighting. The intervention also shows how digitalization in our everyday lives makes information available that can help individuals overcome salience bias and act more in line with their preferences.
This paper was accepted by Uri Gneezy, behavioral economics.
There is growing interest in the situations in which incentives have a significant effect on positive behaviors, particularly in children. Using a randomized field experiment, we find that incentives increase the fraction of children eating a serving of fruits or vegetables during lunch by 80 percent and reduce the amount of waste by 33 percent. At schools with a larger fraction of low-income children, the increase in the fraction of children who eat a serving of fruits or vegetables is even larger, indicating that incentives successfully target the children who are likely to benefit the most from the increased consumption.
We show that two simple and nonintrusive ‘nudges’–reducing plate size and providing social cues–reduce the amount of food waste in hotel restaurants by around 20%. The results are statistically significant. They are also environmentally substantial as food waste is a major contributor to climate change and other forms of environmental degradation. Given the magnitude of the contribution of food waste to global environmental change, it is surprising that this issue has not received greater attention. The measures reduce the amount of food the restaurants need to purchase, and there is no change in guest satisfaction, making it likely that profits will increase. The measures thus constitute potential win–win opportunities.
Policymakers increasingly use norm-based messages to promote conservation efforts. Despite the apparent success of such strategies, empirical analyses have thus far focused exclusively on short-run effects. From a policy perspective, however, whether and how such strategies influence behavior in the long-run is of equal interest. We partner with a metropolitan water utility to implement a natural field experiment examining the effect of such messages on longer-run patterns of water use. Empirical results are striking. While appeals to pro-social preferences affect short-run patterns of water use, only messages augmented with social comparisons have a lasting impact on water demand.
The habit discontinuity hypothesis states that when a context change disrupts individuals’ habits, a window opens in which behavior is more likely to be deliberately considered. The self-activation hypothesis states that when values incorporated in the self-concept are activated, these are more likely to guide behavior. Combining these two hypotheses, it was predicted that context change enhances the likelihood that important values are considered and guide behavior. This prediction was tested in the domain of travel mode choices among university employees who had recently moved versus had not recently moved residence. As was anticipated, participants who had recently moved and were environmentally concerned used the car less frequently for commuting to work. This was found not only when compared to those who were low on environmental concern (which would be a trivial finding), but also to those who were environmentally concerned but had not recently moved. The effects were controlled for a range of background variables. The results support the notion that context change can activate important values that guide the process of negotiating sustainable behaviors.
Previous efforts to use incentives for weight loss have resulted in substantial weight regain after 16 weeks.
To evaluate a longer term weight loss intervention using financial incentives.
A 32-week, three-arm randomized controlled trial of financial incentives for weight loss consisting of a 24-week weight loss phase during which all participants were given a weight loss goal of 1 pound per week, followed by an 8-week maintenance phase.
Veterans who were patients at the Philadelphia Veterans Affairs Medical Center with BMIs of 30-40.
Participants were randomly assigned to participate in either a weight-monitoring program involving a consultation with a dietician and monthly weigh-ins (control condition), or the same program with one of two financial incentive plans. Both incentive arms used deposit contracts (DC) in which participants put their own money at risk (matched 1:1), which they lost if they failed to lose weight. In one incentive arm participants were told that the period after 24 weeks was for weight-loss maintenance; in the other, no such distinction was made.
Weight loss after 32 weeks.
Results were analyzed using intention-to-treat. There was no difference in weight loss between the incentive arms (P = 0.80). Incentive participants lost more weight than control participants [mean DC = 8.70 pounds, mean control = 1.17, P = 0.04, 95% CI of the difference in means (0.56, 14.50)]. Follow-up data 36 weeks after the 32-week intervention had ended indicated weight regain; the net weight loss between the incentive and control groups was no longer significant (mean DC = 1.2 pounds, 95% CI, -2.58-5.00; mean control = 0.27, 95% CI, -3.77-4.30, P = 0.76).
Financial incentives produced significant weight loss over an 8-month intervention; however, participants regained weight post-intervention.
Background:
Smoking is the leading preventable cause of premature death in the United States. Previous studies of financial incentives for smoking cessation in work settings have not shown that such incentives have significant effects on cessation rates, but these studies have had limited power, and the incentives used may have been insufficient.
Methods:
We randomly assigned 878 employees of a multinational company based in the United States to receive information about smoking-cessation programs (442 employees) or to receive information about programs plus financial incentives (436 employees). The financial incentives were 250 for cessation of smoking within 6 months after study enrollment, as confirmed by a biochemical test, and $400 for abstinence for an additional 6 months after the initial cessation, as confirmed by a biochemical test. Individual participants were stratified according to work site, heavy or nonheavy smoking, and income. The primary end point was smoking cessation 9 or 12 months after enrollment, depending on whether initial cessation was reported at 3 or 6 months. Secondary end points were smoking cessation within the first 6 months after enrollment and rates of participation in and completion of smoking-cessation programs.
Results:
The incentive group had significantly higher rates of smoking cessation than did the information-only group 9 or 12 months after enrollment (14.7% vs. 5.0%, P<0.001) and 15 or 18 months after enrollment (9.4% vs. 3.6%, P<0.001). Incentive-group participants also had significantly higher rates of enrollment in a smoking-cessation program (15.4% vs. 5.4%, P<0.001), completion of a smoking-cessation program (10.8% vs. 2.5%, P<0.001), and smoking cessation within the first 6 months after enrollment (20.9% vs. 11.8%, P<0.001).
Conclusions:
In this study of employees of one large company, financial incentives for smoking cessation significantly increased the rates of smoking cessation. (ClinicalTrials.gov number, NCT00128375.)
Global food consumption threatens climate stability and ecosystem resilience. Because hard regulation of food choice through taxes and bans is politically difficult, behavioral approaches provide a promising alternative, given that they influence food choice to a meaningful extent. We test the effect of framing of a menu on the choice of ordering climate-friendly dishes in a randomized controlled experiment. Rearranging the menu in favor of vegetarian food has a large and significant effect on the willingness to order a vegetarian dish instead of meat. Our results demonstrate that small, inexpensive interventions can be used toward decreasing carbon emissions from food consumption.
Reducing meat consumption is considered to have great potential to mitigate food-related greenhouse gas (GHG) emissions. I conducted a field experiment with two restaurants to test if nudging can increase the consumption of vegetarian food. At the treated restaurant, the salience of the vegetarian option was increased by changing the menu order and enhancing the visibility of the vegetarian dish. The other restaurant served as a control. Daily sales data on the three main dishes sold were collected from September 2015 until June 2016. Results show that the nudge increased the share of vegetarian lunches sold by on average 6 percentage points, and that the treatment effect increased over time. The change in behavior is partly persistent, as the share of vegetarian lunches sold remained 4 percentage points higher after the intervention ended than before the experiment. The intervention reduced GHG emissions from food sales by around 5 percent.
I use a field experiment in rural Kenya to study how temporary incentives to save impact long-run economic outcomes. Study participants randomly selected to receive large temporary interest rates on an individual bank account had significantly more income and assets 2.5-3.5 years after the interest rates expired. These changes are much larger than the short-run impacts on experimental bank account use and almost entirely driven by growth in entrepreneurship. In contrast, interest rates on joint accounts and modest cash payments did not significantly impact long-run economic outcomes.
This paper presents results from two large-scale natural field experiments that tested the effect of social norm messages on tax compliance. Using administrative data from > 200,000 individuals in the United Kingdom, we show that including social norm messages in standard reminder letters increases payment rates for overdue tax. This result offers a rare example of social norm messages affecting tax compliance behavior in a real world setting. We find no evidence that loss framing is more effective than gain framing. Descriptive norms appear to be more effective than injunctive norms. Messages referring to public services or financial information also significantly increased payment rates. The field experiments accelerated the collection of tax revenue at little cost.
In a field experiment, we examined whether conveying descriptive social norms (e.g., “this is what most people do”) increases charitable giving. Additionally, we examined whether people are more likely to conform to the local norms of one’s immediate environment than to more global norms extending beyond one’s local environment. University students received a charity organization’s information brochure and were asked for a monetary contribution. An experimental descriptive norm manipulation was embedded in the brochure. We found that providing people with descriptive norms increased charitable giving substantially compared with industry standard altruistic appeals (control condition). Moreover, conveying local norms were more effective in increasing charitable giving than conveying global norms. Practical implications for charity organizations and marketing are proposed.
Many countries use substantial public funds to subsidize reductions in negative externalities. Such policy designs create asymmetric incentives because increases in externalities remain unpriced. I investigate the implications of such policies by using a regression discontinuity design in California's electricity rebate program. Using household-level panel data, I find that the incentive produced precisely estimated zero treatment effects on energy conservation in coastal areas. In contrast, the rebate induced short-run and long-run consumption reductions in inland areas. Income, climate, and air conditioner saturation significantly drive the heterogeneity. Finally, I provide a cost-effectiveness analysis and investigate how to improve the policy design.
Increasing attention is being paid to behavioural economics in the social sciences and in public policy. We attempt to gather up the effects based on previous reviews of the literature and show the implications for transport and energy consumption. We show that there are several behavioural aspects of incentives on individual behaviour. We also show that there are a number of contextual factors on individual behaviour, such as messengers, norms, defaults, salience, priming, affect, commitment, and ego. We show the implications of this research for experimentation, and the measurement of wellbeing. In particular, we argue that transport research should use field experiments to carefully demonstrate causality in the evaluation of interventions.
This paper demonstrates that community-based social marketing techniques can be successfully used to affect people’s transportation awareness and behavior, as deployed in Washington State’s King County Metro Transit’s In Motion program. The In Motion approach focuses on neighborhood-based outreach instead of a more typical employer-based trip reduction program. In addition, In Motion addresses the potential to change any trip from drive alone to an alternative mode instead of focusing exclusively on commute trips. In Motion provides neighborhood residents with incentives to try driving less, raises individual awareness of alternative travel options, and helps break the automatic reflex to drive for all trips. The program was designed to be easily adapted to other neighborhoods with minor modifications in message and materials. The program has been completed in four neighborhoods. Program participants in each neighborhood report increased transit ridership and use of other non-single-occupant vehicle modes, such as carpooling, biking, and walking. The pre- and postparticipant reported mode shares for each In Motion program indicate a 24% to >50% decrease in driving alone and a 20% to almost 50% increase in transit use. These self-reported numbers are supported by bus stop counts and analysis of overall transit ridership. The In Motion program has had promising results in urban and suburban neighborhoods and has been positively received by residents and businesses. King County Metro Transit continues to expand the program to new geographic areas in King County and to explore innovative approaches to establish partnerships and leverage funding for expanded applications.
Rapidly growing health-care costs have fueled interest in using financial incentives to improve health behaviors. Most of the research on financial incentives outside of clinical studies has been observational, limiting our ability to make causal inferences on their effectiveness. The few carefully-designed studies have generally found little lasting effect on behavior after the incentive program ended. We report on a large field experiment with employees of a Fortune 500 company which offered incentives for using the company gym. In addition to understanding the effects of incentives alone, we investigate a novel approach to generate lasting behavior change using self-funded commitment contracts. At the end of incentive period, half of the incentive group were offered the opportunity to create a self-funded commitment contract to motivate their own behavior. Workers responded strongly during the incentive period, doubling their rate of use of the company gym. After the incentive period ended, we find that those offered incentives only continued to attend at higher rates, but the effect was quite modest in magnitude. The availability of a commitment contract, however, substantially improved the long-run effects of the incentive program both during the commitment period and well beyond, offering a promising new approach to increasing the long-run effect of incentive programs.Institutional subscribers to the NBER working paper series, and residents of developing countries may download this paper without additional charge at www.nber.org.
It is widely recognized that communications that activate social norms can be effective in producing societally beneficial conduct. Not so well recognized are the circumstances under which normative information can backfire to produce the opposite of what a communicator intends. There is an understandable, but misguided, tendency to try to mobilize action against a problem by depicting it as regrettably frequent. Information campaigns emphasize that alcohol and drug use is intolerably high, that adolescent suicide rates are alarming, and—most relevant to this article—that rampant polluters are spoiling the environment. Although these claims may be both true and well intentioned, the campaigns' creators have missed something critically important: Within the statement “Many people are doing this undesirable thing” lurks the powerful and undercutting normative message “Many people are doing this.” Only by aligning descriptive norms (what people typically do) with injunctive norms (what people typically approve or disapprove) can one optimize the power of normative appeals. Communicators who fail to recognize the distinction between these two types of norms imperil their persuasive efforts.
The aim of this study was to investigate whether a temporary structural change would induce a lasting increase in drivers' public transport use. An experiment targeting 43 drivers was carried out, in which a one-month free bus ticket was given to 23 drivers in an experimental group but not to 20 drivers in a control group. Attitudes toward, habits of, and frequency of using automobile and bus were measured immediately before, immediately after, and one month after the one-month long intervention. The results showed that attitudes toward bus were more positive and that the frequency of bus use increased, whereas the habits of using automobile decreased from before the intervention, even one month after the intervention period. Furthermore, the increase in habitual bus use had the largest effect on the increase in the frequency of bus use. The results suggest that a temporary structural change, such as offering auto drivers a temporary free bus ticket, may be an important travel demand management tool for converting automotive travel demand to public-transport travel demand.
Newspapers, book clubs, telephone services and many other subscription services are often marketed to new customers by means of a free or substantially discounted trial period. This article evaluates this method as a means to promote commuting by public transport in a field experiment and based on a solid behavioural–theoretical framework. By measuring important antecedents and mediators, the applied approach offers important insights not only on what behavioural outcomes were produced by the intervention, but why they were produced. Copenhagen car owners received a free month travel card, either alone or together with a customised travel plan or a planning intervention. A control group receiving no intervention was also included. Attitudinal variables, car habits and travel behaviour were measured before and immediately after the intervention and again six months later. The only intervention that had an effect was the free month travel card, which led to a significant increase in commuting by public transport. As expected, the effect was mediated through a change in behavioural intentions rather than a change in perceived constraints. As expected, the effect became weaker when the promotion offer had expired, but an effect was still evident five months later. Possible reasons and implications of this are discussed.
This paper evaluates a pilot program run by a company called OPOWER, previously known as Positive Energy, to mail home energy reports to residential utility consumers. The reports compare a household’s energy use to that of its neighbors and provide energy conservation tips. Using data from randomized natural field experiment at 80,000 treatment and control households in Minnesota, I estimate that the monthly program reduces energy consumption by 1.9 to 2.0 percent relative to baseline. In a treatment arm receiving reports each quarter, the effects decay in the months between letters and again increase upon receipt of the next letter. This suggests either that the energy conservation information is not useful across seasons or, perhaps more interestingly, that consumers’ motivation or attention is malleable and non-durable. I show that “profiling,” or using a statistical decision rule to target the program at households whose observable characteristics suggest larger treatment effects, could substantially improve cost effectiveness in future programs. The effects of this program provide additional evidence that non-price “nudges” can substantially affect consumer behavior.
To investigate the process of habit formation in everyday life, 96 volunteers chose an eating, drinking or activity behaviour to carry out daily in the same context (for example 'after breakfast') for 12 weeks. They completed the self-report habit index (SRHI) each day and recorded whether they carried out the behaviour. The majority (82) of participants provided sufficient data for analysis, and increases in automaticity (calculated with a sub-set of SRHI items) were examined over the study period. Nonlinear regressions fitted an asymptotic curve to each individual's automaticity scores over the 84 days. The model fitted for 62 individuals, of whom 39 showed a good fit. Performing the behaviour more consistently was associated with better model fit. The time it took participants to reach 95% of their asymptote of automaticity ranged from 18 to 254 days; indicating considerable variation in how long it takes people to reach their limit of automaticity and highlighting that it can take a very long time. Missing one opportunity to perform the behaviour did not materially affect the habit formation process. With repetition of a behaviour in a consistent context, automaticity increases following an asymptotic curve which can be modelled at the individual level.
Unhealthy behavior is a major cause of poor health outcomes and high health care costs. In this paper we describe an agenda for research to guide broader use of patient-targeted financial incentives, either in conjunction with provider-targeted financial incentives (pay-for-performance, or P4P) or in clinical contexts where provider-targeted approaches are unlikely to be effective. We discuss evidence of proven effectiveness and limitations of the existing evidence, reasons for underuse of these approaches, and options for achieving wider use. Patient-targeted incentives have great potential, and systematic testing will help determine how they can best be used to improve population health.
Despite a long tradition of effectiveness in laboratory tests, normative messages have had mixed success in changing behavior in field contexts, with some studies showing boomerang effects. To test a theoretical account of this inconsistency, we conducted a field experiment in which normative messages were used to promote household energy conservation. As predicted, a descriptive normative message detailing average neighborhood usage produced either desirable energy savings or the undesirable boomerang effect, depending on whether households were already consuming at a low or high rate. Also as predicted, adding an injunctive message (conveying social approval or disapproval) eliminated the boomerang effect. The results offer an explanation for the mixed success of persuasive appeals based on social norms and suggest how such appeals should be properly crafted.
To test the ability of two levels of modest financial incentives to encourage weight loss among overweight employees.
This study used a randomized design with measurements at baseline, 3, and 6 months and two levels of financial incentives (14 per percentage point of weight lost). Payments were structured so that all participants had equal ability to obtain the incentives during the study period.
At 3 months, participants with no financial incentive lost 2 pounds, those in the 14 group lost 4.7 pounds. Between baseline and 6 months, when the financial gains were equalized, weight losses were similar across groups.
This study revealed that modest financial incentives can be effective in motivating overweight employees to lose weight.
Mobility management (MM) is a transportation management policy that uses “soft” measures to attempt to reduce car use and promote sustainable transportation modes such as public transport, bicycles, and walking. Using communication and other means, MM induces voluntarily change towards more sustainable transportation modes. We implemented MM marketing to promote an experimental community bus service. This project had two components: a questionnaire conducted in the service area and a monthly newsletter. The questionnaire was more than a survey; it also communicated information about the bus and helped promote bus use. One month after the survey, we implemented a follow-up survey targeting the initial survey respondents. Results suggest that the MM program produced a general increase in bus use, as well as mouth-to-mouth advertising, that helped promote bus use. Copyright Springer Science+Business Media B.V. 2007
Incentives to exercise
- Charness
Så reser vi i Skåne Resvaneundersökningen 2018
- Hedlund
Climate change 2014: mitigation of climate change
- European Environment Agency
Summary Report: Commuting in Stockholm, Gothenburg and Malmö - a current state analysis
- Trafa
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- Skold