Adolescence is a period of remarkable psychosocial and neural development. Many life-long health habits are established during adolescence, making it a window of opportunity for health promotion. One way to promote adolescent health is through mass and social media campaigns. Although some health media campaigns that target adolescents are effective in changing health-relevant cognitions and behaviors, there is considerable room for improving these outcomes. Recent advancements combining neuroimaging tools and health persuasion have suggested key neural mechanisms underlying behavior change and retransmission of health-relevant ideas and norms in adults. This line of work highlights the integral role of the brain's value system in health persuasion and its importance for improving campaign design and effectiveness. Less is known about how these insights could be leveraged to inform adolescent health persuasion. In this article, we review what is known and unknown about the development of the brain's value system and its connections with cognitive control and social cognition systems across adolescence. Combining these insights, we propose that neuroimaging tools offer unique possibilities that could improve adolescent media health campaigns and promote adolescent well-being.

Are people more likely to (mis)interpret information so that it aligns with their ideological identity when relying on feelings compared to when engaging in analytical thinking? Or is it the other way around: Does deliberation increase the propensity to (mis)interpret information to confirm existing political views? In a behavioral experiment, participants (n = 1207, Swedish sample) assessed numerical information concerning the effects of gender quotas and immigration either under time pressure or under no time pressure. To measure trait differences in cognitive sophistication, we also collected data on numeric ability. We found clear evidence of motivated reasoning when assessing both the effects of gender quotas on companies’ financial results and the effect of refugee intake on crime rates. Subjects who prioritized equality over liberty on the labor market were 13 percentage points less likely to correctly assess numerical information depicting that companies that used gender quotas when hiring made less profit. Subjects who classified themselves as ‘Swedes’ rather than ‘World citizens’ were 14 percentage points less likely to correctly assess numerical information depicting that crime rates decreased following immigration. Time pressure did not affect the likelihood to engage in motivated reasoning, while subjects with higher numeric ability were less likely to engage in motivated reasoning when analyzing information concerning refugee intake, but more likely to engage in motivated reasoning when analyzing information regarding the effect of gender quotas. Together these results indicate that motivated reasoning is primarily driven by individual differences in analytical thinking at the trait level and not by situational factors such as time pressure, and that whether motivated reasoning is primarily driven by analysis or feelings depends on the topic at hand.

I comment on Sunstein's paper proposing ‘Hayekian behavioural economics’. In essence, Sunstein is merely renaming a familiar approach to normative economics, initiated in Sunstein and Thaler's seminal 2003 paper. I argue that this approach cannot fairly be described as in the spirit of Hayek's work. Sunstein's approach is based on a ‘constructivist’ conception of rationality that Hayek consistently criticized. Although both Hayek and Sunstein address ‘knowledge problems’, the two problems are fundamentally different. I develop what I claim are truly Hayekian critiques of Sunstein's claim that fuel economy mandates can be more Hayekian than carbon taxes.

This study investigated determinants of the willingness to get vaccinated in India and examined the relationship between engagement in preventive behaviours and vaccine uptake intent. A large-scale online survey covering aspects of COVID-19 preventive behaviours, vaccination status, moral emotions, trust in others, role models, and socio-demographics was used. A total of 953 Indians participated in the survey between May and June 2021, of which 770 contained valid data on vaccination status. Past preventive health behaviours (PHBs) such as avoiding social gatherings, higher interpersonal trust, and moral emotions were robustly associated with the willingness to take a COVID-19 vaccine. Results also showed that unvaccinated individuals were less likely to follow other PHBs, like wearing a mask; past COVID-19 infection status was associated with similar lower adherence to PHBs. Given the strong associations between positive moral emotions, like gratitude, and vaccine uptake intent (especially in the unvaccinated subsample), targeted communication interventions can boost uptake intent, and subsequently vaccine uptake, in jurisdictions with low vaccination rates.

With the increasing availability of life-saving vaccines against the SARS-CoV-2 virus, government agencies face the challenge of promoting vaccine uptake. Thus, encouraging vaccine uptake marks an urgent policy challenge in fighting the COVID-19 pandemic. This study builds on the theory of psychological ownership to design a behaviorally inspired local government vaccination campaign. We conducted a large-scale, cluster-randomized field experiment (N = 27,298 residents nested in 6,442 addresses) delivered to all registered residents of a German municipality via an official mailing campaign. The campaign included a psychological ownership intervention designed to boost residents’ intentions to get vaccinated – measured through unique link clicks on a municipal website where people can schedule a COVID-19 vaccination appointment. Findings suggest that adding possessive pronouns (i.e., ‘YOUR vaccination’) increases vaccination intentions by 39%, or 2.5 percentage points (p < 0.0001 [95% CI = 1.8%, 3.3%], control letter: 6.4%, treatment letter: 8.9%). The discussion outlines the value of using psychological ownership-based nudge interventions to increase vaccine uptake and other desirable behaviors.

Why and when does outrage grow? This essay, based on the 2018 LSE Behavioural Public Policy Lecture delivered in February 2018, explores two potential answers. The first points to a revision or weakening of social norms, which leads people to express outrage that they had previously suppressed. The second points to a revision or weakening of social norms, which leads people to express outrage that they had not previously felt (and may or may not now feel). The intensity of outrage is often a product of what is most salient. It is also a product of ‘normalization’; people compare apparently outrageous behavior to behavior falling into the same category in which it is observed, and do not compare it to other cases, which leads to predictable incoherence in judgments. These points bear on the #MeToo movement of 2017 and 2018 and the rise and fall (and rise again, and fall again) of discrimination on the basis of sex and race (and also religion and ethnicity).

Recently, defaults have become celebrated as a low-cost and easy-to-implement nudge for promoting positive outcomes, both at an individual and societal level. In the present research, we conducted a large-scale field experiment (N = 32,508) in an educational context to test the effectiveness of a default intervention in promoting participation in a potentially beneficial achievement test. We found that a default manipulation increased the rate at which high school students registered to take the test but failed to produce a significant change in students’ actual rate of test-taking. These results join past literature documenting robust effects of default framings on initial choice but marked variability in the extent to which those choices ultimately translate to real-world outcomes. We suggest that this variability is attributable to differences in choice-to-outcome pathways – the extent to which the initial choice is causally determinative of the outcome.

Whether nudges succeed in promoting pro-environmental behavior strongly depends on their public acceptance. Prior literature shows that the framing of nudges, i.e., whether they address the individual (personal framing) or the society (societal framing), is one critical factor in determining nudging acceptance. Since a personal framing highlights the costs individuals have to bear to comply, we hypothesize that people accept nudges more when addressing the general public rather than themselves personally. We expect the framing effect to be stronger for nudges that elicit high-effort behavior than low-effort behavior. Results of multilevel linear regression analyses in two online experiments (nStudy 1 = 294, nobs = 4,410; nStudy 2 = 565, nobs = 11,300) reveal an opposite pattern: People accept nudges more when personally (vs societally) framed. As predicted, nudges receive higher support when the promoted behavior is perceived as low effort. Exploratory path analysis in Study 2 shows that the perceived effectiveness of the nudge mediates the positive relation between personal framing and nudging acceptance. This project provides novel insights on facilitators and barriers in nudging acceptance and their implications for policy-making.

Many proponents of behavioural public policy work within a broadly consequentialist framework. From this perspective, the ultimate aim of public policy is to maximise utility, happiness, welfare, the satisfaction of preferences, or similar; and the behavioural aspect of public policy aims to harness a knowledge of human psychology to make this maximisation more effective. In particular, behavioural insights may be crucial to help policy-makers ‘save us from ourselves’ by helping citizens avoid falling into non-rational choices, for example, through framing effects, failures of will-power, and so on. But an alternative reading of the psychological literature is that human thoughts and actions are not biased from a rational standard, but are simply systematically inconsistent. If so, then utility and similar notions are not well defined either for individuals or as an objective of public policy. I argue that a different, contractarian viewpoint is required: that the determination of public policy is continuous with the formation of agreements we make with each other at all scales, from momentary social interactions, to linguistic and social conventions, to collective decisions by groups and organisations. Behavioural factors do not over-ride, but can (among many other factors) inform, our collective decision-making process. The point of behavioural insights in public policy is primarily to inform and enrich public debate when deciding the rules by which we should like to live.

While it is broadly accepted that individuals are boundedly rational, the meaning of these boundaries and what to do about them has generated a debate between two different views: one that defends nudging as the best possible way to improve the outcome of people's decision and one that criticizes their use. This debate occurs at an instrumental level, conceiving decisions under a goal-oriented perspective. I propose that adding the role of values (axiological rationality) to the discussion can shed new light, not only on this debate, but also on nudges themselves, clarifying and enriching some arguments in the discussion about autonomy and efficiency. This approach will not only be more comprehensive, but it will also increase the effectiveness of nudges by tackling the different components of our rationality. Nudges should not only be goal-oriented; they should also be educational. Non-educational nudges should be used in conjunction with educational interventions. I will illustrate my position with two examples: vaccination policies and nudges in the use of seatbelts.

I highlight two important factors particular to less-developed countries that can bias evidence generation and contribute to the ‘voltage drop’ in programme benefits, moving from field research experiments to policy implementation at scale. The first is the non-linear increase in information processing and coordination costs associated with upscaling in less-developed countries, given limited state capacity and rigid organizational hierarchies. The second is political bias in the choice of programmes considered for rigorous evaluation itself, resulting in distorted evidence and policy choice. These two factors raise considerations that complement the economics-based approach outlined by Al-Ubaydli et al. in the quest for more rigorous, evidence-based policy.

This randomised online experiment aimed to investigate how eco-labelling and social nudging influenced sustainable food choice, as well as consider the effect of motivation to act sustainably. Participants were UK adults ≥18 years (n = 1399). Participants were asked to choose a hypothetical meal (beef, chicken or vegetarian burrito) and were randomly allocated to one of three conditions varying in labelling: eco-labelling; social nudge or control (no label). Co-primary outcomes were the frequency that the vegetarian and chicken burritos were chosen (i.e., the more sustainable food choices). There was evidence that more vegetarian (OR = 3.3 [95% CI 2.0, 5.3]) and chicken (OR = 2.5 [95% CI 1.8, 3.4]) burrito choices were made in the eco-label condition, over the beef burrito, compared to the control condition. In the social nudge condition, there was evidence that participants chose a vegetarian burrito over a beef burrito (OR = 1.7 [95% CI 1.1, 2.7]), but not a vegetarian burrito over a chicken burrito (OR = 1.4 [95% CI 0.9, 2.2]). Although both labels were effective at promoting participants to make more sustainable food choices, the eco-label was the most effective. Choice of burrito was modified by motivation to act sustainably across all conditions. This study suggests that future policy could include eco-labelling and/or a social nudge to reduce meat consumption and meet global climate change targets.

Recently, there has been a lively discussion of “Hayekian Behavioral Economics” in Behavioral Public Policy). We aim to contribute to this debate by identifying the main building blocks of a Hayekian psychology. We highlight that the starting point for Hayek was the quest to understand why humans are typically quite successful in navigating the world. In Hayek's framework, the individual mind is conceptualized as a “system within a system”, i.e., the mind is a complex adaptive system that is continuously interacting with the wider socio-cultural system. Three core ideas are central to a Hayekian psychology: subjectivity, learning and adaptation. We argue that these ideas are quite different from the still dominant heuristics-and-biases perspective and lead to different emphases in economic and social science explanations. One, economists should be cautious in their interpretation of experimental findings since subjective meaning is central to agents' behavior. Two, static and isolated models of individuals' biases might underestimate people's capacity to learn with and from others. And three, despite complex processes of adaptation of the mind and the market, a Hayekian framework is consistent with economists' “explanations of the principle” and “pattern predictions.”

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 and explore an unobtrusive approach that can speak to the immediate emotional impacts of a nudge: automatic facial expression coding. In an exploratory lab study, we use facial expression coding to assess the short-run emotional impact of being presented with calorie information about a popcorn snack in the context of a stylised ‘Cinema experience’. The results of the study indicate that calorie information has heterogeneous impacts on people's likelihood of choosing the snack and on the emotions they experience during the moment of choice which varies based on their level of health-consciousness. The information does not, however, affect the emotions people go on to experience while viewing movie clips, suggesting that the emotional effects of the information are short-lived. We conclude by emphasising the potential of automatic facial expression coding to provide new insights into the immediate emotional impacts of nudges and calling for further research into this promising technique.

In the past decades, behavioral economics has credibly identified numerous decision-making biases leading people to make choices they would not have made if better informed about the long-term consequences of their actions. This has given rise to a new reason for government interventions: internalities. In contrast to traditional reasons for government intervention, such as redistribution and externalities, overcoming internalities often involves the use of paternalistic policies. We investigate theoretically and empirically the formation of attitudes toward paternalistic policies. Theoretically, we focus on the role of self-interest and distinguish between self-interest as construed for the rational decision-maker, self-interest when self-control problems are present, and self-interest when procedural or expressive elements, such as autonomy, matter. Empirically, we employ two novel data sets: a Danish survey on political opinion combined with administrative data on actual behavior and a large-scale cross-country survey to analyze attitudes toward paternalistic policies in the health and financial domains. We show that targets of paternalism are more opposed to paternalism than non-targets both in Denmark and across nine Western democracies and rely on our theoretical priors to explore mechanisms that can explain these attitudes.

Nancy Cartwright argues that evidence-based policies should not only rely on randomized controlled trials (RCTs) to test their effectiveness – they should also use horizontal and vertical searches to find support factors and causal principles that help define how those policies work. This paper aims at analyzing Cartwright's epistemology regarding evidence-based policies and their use of RCTs while applying her findings to current research involving nudges as behavioral public policy interventions. Holding a narrowly instrumental view of rationality, nudge theory tends to neglect other expressive components. Policymakers, in their quest for causal principles, should consider the expressive rationality of individuals in their research. This inclusion would not only increase the effectiveness of nudges, but also address some ethical issues related to people's autonomy when targeted by these interventions.

Most applications of behavioral economics, finance, and accounting research to policy focus on alleviating the adverse effects of individuals’ biases and cognitive constraints (e.g. through investor protection rules or nudges). We argue that it is equally important to understand how psychological bias can cause a collective dysfunction – bad accounting policy and financial regulation. We discuss here how psychological bias on the part of the designers of regulation and accounting policy (voters, regulators, politicians, media commentators, managers, users, auditors, and financial professionals) has helped shape existing regulation, and how an understanding of this process can improve regulation in the future. Regulatory ideologies are belief systems that have evolved and spread by virtue of their ability to recruit psychological biases. We examine how several psychological factors and social processes affect regulatory ideologies.

The paper by Paul Frijters, Andrew E. Clark, Christian Krekel and Richard Layard is a timely attempt to move subjective wellbeing (SWB) to the center of policy attention. I am essentially making three points. First of all, for this enterprise to be successful, one needs to have very solid evidence on what improves SWB and what does not. If policies are proposed that turn out not to improve SWB (or do so far less than expected), then the enterprise of making SWB the centerpiece of policy may be discredited before it has begun in earnest. As an example of this concern, my second point is that raising the incomes of all may have very disappointing effects on measured SWB. My third point is that at the current state of knowledge, the most fertile ground for learning about what works is to exploit international comparisons of policies and how these affect a nation's SWB.

Times of emergency often serve as triggers for the creation of new policy. Such policies may involve restriction of human rights, and various mechanisms can be used to mitigate the severity of such restrictions. One such mechanism is the temporary measure. A series of three experiments examined the potential of temporary measures for increasing the likelihood of approval of rights-restricting policy and the role of time – both prospectively and retrospectively – in the willingness to restrict human rights. We find that behavioural examination confirms the concerns expressed in the literature regarding temporary legislation. Participants asked to approve a rights-restricting policy were more willing to approve a temporary measure when it was presented as a compromise, and they were more willing to extend a rights-restricting policy when it had previously been implemented. These findings indicate a possible slippery slope effect in temporary legislation: policymakers might be persuaded to approve measures they would not otherwise approve when those measures are temporary or when they have been previously approved by others.

Paternalistic nudging and framing aim to correct flaws in deliberation by relying on the same cognitive mechanisms that create those flaws. Regarding some choices as flawed and in need of correction requires some standard of correctness. In their well-known book, Nudge, Thaler and Sunstein take the individual's own “purified” preferences to be that standard, which is inconsistent with the finding of behavioral economics that individuals do not have a stable preference ranking of alternatives, but instead construct their preferences when faced with a choice. This essay defends an alternative, readily usable standard to judge whether individuals are choosing badly and whether nudges can help them to choose better.