C. Sunstein

Harvard University | Harvard · Harvard Law School

People are often reluctant to make decisions by calculating the costs and benefits of alternative courses of action in particular cases. Knowing, in addition, that they may err, people and institutions often resort to second-order strategies for reducing the burdens of, and risk of error in, first-order decisions. They make a second order decision...

Choice can be an extraordinary benefit or an immense burden. In some contexts, people choose not to choose, or would do so if they were asked. In part because of limitations of “bandwidth,” and in part because of awareness of their own lack of information and potential biases, people sometimes want other people to choose for them. For example, many...

Careful attention to choice architecture promises to open up new possibilities for environmental protection – possibilities that go well beyond the standard tools of economic incentives, mandates, and bans. How, for example, do consumers choose between environmentally-friendly products or services and alternatives that are potentially damaging to t...

How is constitutionalism possible, when people disagree on so many questions about what is good and what is right? This essay, written for a special issue of Social Research on Difficult Decisions, explores the role of two kinds of incompletely theorized agreements amidst sharp disagreements about the largest issues in social life. The first consis...

The idea of libertarian paternalism might seem to be an oxymoron, but it is both possible and legitimate for private and public institutions to affect behavior while also respecting freedom of choice. Often people's preferences are ill-formed, and their choices will inevitably be influenced by default rules, framing effects, and starting points. In...

Food consumption and production contribute significantly to global greenhouse gas emissions , making them crucial entry points for mitigating climate change and maintaining a liveable planet. Over the past two decades, food policy initiatives have explored interventions to reshape production and consumption patterns, focusing on reducing food waste...

In the current era, product differentiation is increasing; it is often fueled by big data and artificial intelligence (AI). Whereas product differentiation is generally welfare enhancing when consumers are informed and fully rational, such differentiation might reduce welfare when consumers suffer from misperceptions, either because of a lack of in...

Sometimes legal systems are “noisy”; they show unjustified variability or “scatter,” which means that what emerges is likely to be unpredictable and unfair. Potential examples include assessment of whether a risk is “significant” or “unreasonable,” fines for environmental harms or safety violations, compensatory damage awards for libel, pain and su...

Scientific evidence regularly guides policy decisions¹, with behavioural science increasingly part of this process². In April 2020, an influential paper³ proposed 19 policy recommendations (‘claims’) detailing how evidence from behavioural science could contribute to efforts to reduce impacts and end the COVID-19 pandemic. Here we assess 747 pandem...

The Covid pandemic has yielded new insights into psychological vaccine acceptance factors. This knowledge serves as a basis for behavioral and communication interventions that can increase vaccination readiness for other diseases.

Machine learning algorithms are increasingly able to predict what goods and services particular people will buy, and at what price. It is possible to imagine a situation in which relatively uniform, or coarsely set, prices and product characteristics are replaced by far more in the way of individualization. Companies might, for example, offer peopl...

Fake news emerged as an apparent global problem during the 2016 U.S. Presidential election. Addressing it requires a multidisciplinary effort to define the nature and extent of the problem, detect fake news in real time, and mitigate its potentially harmful effects. This will require a better understanding of how the Internet spreads content, how p...

This paper explores the application of message framing as a management practice to promote change in employee behaviour for corporate sustainability. We conduct a field experiment in a German automotive company to test the effects of three different frames (emotional, normative and gain) on pro-environmental actions in relation to electric vehicle...

In recent years, many governments have shown a keen interest in “nudges” — approaches to law and policy that maintain freedom of choice, but that steer people in certain directions. Yet to date, there has been little evidence on whether citizens of various societies support nudges and nudging. We report the results of nationally representative surv...

Social and behavioral science research proliferated during the COVID-19 pandemic, reflecting the substantial increase in influence of behavioral science in public health and public policy more broadly. This review presents a comprehensive assessment of 742 scientific articles on human behavior during COVID-19. Two independent teams evaluated 19 sub...

Background: COVID-19 booster vaccine uptake rates are behind the rate of primary vaccination in many countries. Governments and non-governmental institutions rely on a range of interventions aiming to increase booster uptake. Yet, little is known how experts and the general public evaluate these interventions. Methods: We applied a novel crowdsourc...

Background: COVID-19 booster vaccine uptake rates are behind the rate of primary vaccination in many countries. Governments and non-governmental institutions rely on a range of interventions aiming to increase booster uptake. Yet, little is known how experts and the general public evaluate these interventions. Methods: We applied a novel crowdsourc...

Why people do or do not change their beliefs has been a long-standing puzzle. Sometimes people hold onto false beliefs despite ample contradictory evidence; sometimes they change their beliefs without sufficient reason. Here, we propose that the utility of a belief is derived from the potential outcomes associated with holding it. Outcomes can be i...

Although there has been a proliferation of research and policy work into how nudges shape people's behaviour, most studies stop far short of consumer welfare analysis. In the current work, we critically reflect on recent efforts to provide insights into the consumer welfare impact of nudges using willingness to pay and subjective well-being reports...

Why people do or do not change their beliefs has been a long-standing puzzle. Sometimes people hold onto false beliefs despite ample contradictory evidence; sometimes they change their beliefs without sufficient reason. Here, we propose that the utility of a belief is derived from the potential outcomes of holding it. Outcomes can be internal (e.g....

Nudges are tools to achieve behavioural change. To evaluate nudges, it is essential to consider not only their overall welfare effects but also their distributional effects. Some nudges will not help, and might hurt, identifiable groups. More targeted, personalized nudging may be needed to maximize social welfare and promote distributive justice.

Cultivation theory assumes that frequent exposure to certain media can lead people to perceive the real world through the lens of their preferred media. This led to the research question of whether fans of science fiction who are accustomed to seeing problem solving based on science and technology are prone to accept science- and technology-based i...

In philosophy, economics, and law, the idea of voluntary agreements plays a central role. But contractarianism in political philosophy stands (or falls) on altogether different grounds from enthusiasm for contractual ordering in economics and law. Protection of voluntary agreements, and of personal agency, might well be justified on deontological g...

Why are lies wrong? The Kantian answer sees lies as a close cousin to coercion; they are a violation of individual autonomy and a demonstration of contempt. By contrast, the utilitarian answer is that lies are likely to lead to terrible consequences, sometimes because they obliterate trust, sometime because they substitute the liar’s will for that...

With respect to the views of dead thinkers, answers to many particular questions are often interpretive in Ronald Dworkin's sense. Such answers must attempt (1) to fit the materials to be interpreted and (2) to justify them, that is, to put them in the best constructive light. What looks like (1), or what purports to be (1), is often (2). That is,...

How we became so burdened by red tape and unnecessary paperwork, and why we must do better. We've all had to fight our way through administrative sludge—filling out complicated online forms, mailing in paperwork, standing in line at the motor vehicle registry. This kind of red tape is a nuisance, but, as Cass Sunstein shows in Sludge, it can also i...

To mitigate climate change, food systems must reduce their greenhouse gas emissions. For consumers, this means switching to more plant-based diets and wasting less food. A behaviorally informed policy employing nudges—educative and architectural—can be a cornerstone. Plant-based defaults promise large reduction effects while maintaining freedom of...

What information would people like to have? What information would they prefer to avoid? How does the provision of information bear on welfare? And what does this mean for food policy? Representative surveys in eleven nations find that substantial percentages of people do not want to receive information even when it bears on health, sustainability,...

Careful attention to choice architecture promises to open up new possibilities for reducing greenhouse gas emissions—possibilities that go well beyond, and that may supplement or complement, the standard tools of economic incentives, mandates, and bans. How, for example, do consumers choose between climate-friendly products or services and alternat...

One of Friedrich Hayek's most important arguments pointed to the epistemic advantages of the price system, regarded as an institution. As Hayek showed, the price system incorporates the information held by numerous, dispersed people. Like John Stuart Mill, Hayek also offered an epistemic argument on behalf of freedom of choice. A contemporary chall...

Increasing the uptake of green energy use by households and businesses is a key step toward reducing environmental harm and combating climate change. In a new paper, Liebe et al.1 show that a non-monetary intervention can have massive effects on green energy consumption, leading to substantial reductions in carbon emissions.

Die Verbraucherpolitik verfügt über ein breites Instrumentarium, bestehend aus weichen Instrumenten wie Information und Beratung, Bildung und Befähigung, Organisation und Ermächtigung sowie harten Instrumenten wie Steuern, Abgaben, Subventionen und der Regulierung durch Recht. In jüngerer Zeit wird verstärkt eine evidenzbasierte Politik angestrebt,...

As health care becomes increasingly personalized to the needs and values of individual patients, informational interventions that aim to inform and debias consumer decision-making are likely to become important tools. In a randomized controlled experiment, we explore the effects of providing participants with published fact boxes on the benefits an...

This chapter reports the results of nationally representative surveys in fourteen countries, investigating the attitudes of people towards nudges and nudging, with a particular focus on environmental and health nudges. The countries covered are Australia, Brazil, Canada, China, Denmark, France, Germany, Hungary, Italy, Japan, Russia, South Africa,...

Choice is a key concept of our time. It is a foundational mechanism for every legal order in societies that are, politically, constituted as democracies and, economically, built on the market mechanism. Thus, choice can be understood as an atomic structure that grounds core societal processes. In recent years, however, the debate over the right way...

As intuitive statisticians, human beings suffer from identifiable biases—cognitive and otherwise. Human beings can also be “noisy” in the sense that their judgments show unwanted variability. As a result, public institutions, including those that consist of administrative prosecutors and adjudicators, can be biased, noisy, or both. Both bias and no...

Behavioral science is playing an increasing role in public policy, and it is raising new questions about fundamental issues - the role of government, freedom of choice, paternalism, and human welfare. In diverse nations, public officials are using behavioral findings to combat serious problems - poverty, air pollution, highway safety, COVID-19, dis...

When policymakers focus on costs and benefits, they often find that hard questions become easy – as, for example, when the benefits clearly exceed the costs, or when the costs clearly exceed the benefits. In some cases, however, benefits or costs are difficult to quantify, perhaps because of limitations in scientific knowledge. In extreme cases, po...

Do people from benefit from food labels? When? By how much? Public officials face persistent challenges in answering these questions. In various nations, they use four different approaches: they refuse to do so on the ground that quantification is not feasible; they engage in breakeven analysis; they project end-states, such as economic savings or...

Bestselling author and recipient of the 2018 Holberg Prize, Cass R. Sunstein, explores how more information can make us happy or miserable, and why we sometimes avoid it—but sometimes seek it out. How much information is too much? Do we need to know how many calories are in the giant vat of popcorn that we bought on our way into the movie theater?...

Bestselling author and recipient of the 2018 Holberg Prize, Cass R. Sunstein, explores how more information can make us happy or miserable, and why we sometimes avoid it—but sometimes seek it out. How much information is too much? Do we need to know how many calories are in the giant vat of popcorn that we bought on our way into the movie theater?...

The present paper focuses on green defaults as demand-side policies supporting the uptake of renewable energy in Germany. It sets out to gain a better understanding of whether and for whom green electricity defaults work. The present study is one of the first to use a large-scale data set to investigate this question. We combine micro-level data fr...

Demand-side policies for mitigating climate change based on behavioral insights are gaining increased attention in research and practice. Here we describe a systematic map that catalogues existing research on behaviorally informed interventions targeting changes in consumer food consumption and food waste behavior. The purpose is to gain an overvie...

Preventing discrimination requires that we have means of detecting it, and this can be enormously difficult when human beings are making the underlying decisions. As applied today, algorithms can increase the risk of discrimination. But as we argue here, algorithms by their nature require a far greater level of specificity than is usually possible...

Governments around the world have implemented measures to manage the transmission of coronavirus disease 2019 (COVID-19). While the majority of these measures are proving effective, they have a high social and economic cost, and response strategies are being adjusted. The World Health Organization (WHO) recommends that communities should have a voi...

Public opinion is shaped in significant part by online content, spread via social media and curated algorithmically. The current online ecosystem has been designed predominantly to capture user attention rather than to promote deliberate cognition and autonomous choice; information overload, finely tuned personalization and distorted social cues, i...

There has been considerable recent discussion of the social effects of “liberalism,” which are said to include a growth in out-of-wedlock childbirth, repudiation of traditions (religious and otherwise), a rise in populism, increased reliance on technocracy, inequality, environmental degradation, sexual promiscuity, deterioration of civic associatio...

A growing body of normative work explores whether and how deference to people’s choices might be reconciled with behavioral findings about human error. This work has strong implications for economic analysis of law, cost–benefit analysis, and regulatory policy. In light of behavioral findings, regulators should adopt a working presumption in favor...

The COVID-19 pandemic represents a massive global health crisis. Because the crisis requires large-scale behaviour change and places significant psychological burdens on individuals, insights from the social and behavioural sciences can be used to help align human behaviour with the recommendations of epidemiologists and public health experts. Here...

The COVID-19 pandemic represents a massive, global health crisis. Because the crisis requires large-scale behavior change and poses significant psychological burdens on individuals, insights from the social and behavioural sciences are critical for optimizing pandemic response. Here we review relevant research from a diversity of research areas rel...

Democratic institutions aggregate voters’ preferences about policy options and thereby help determine which policies are implemented. Previous research has, however, suggested that such institutions can also have a direct, positive effect on cooperative and efficient behavior. In a laboratory experiment, we test this suggestion by comparing the eff...

Immense amounts of information are now accessible to people, including information that bears on their past, present and future. An important research challenge is to determine how people decide to seek or avoid information. Here we propose a framework of information-seeking that aims to integrate the diverse motives that drive information-seeking...

Consumers, employees, students and others are often subjected to ‘sludge’: excessive or unjustified frictions, such as paperwork burdens, that cost time or money; that may make life difficult to navigate; that may be frustrating, stigmatizing or humiliating; and that might end up depriving people of access to important goods, opportunities and serv...