Evolutionary explanations for behavioral findings are often both fascinating and plausible. But even so, they do not establish that people are acting rationally, that they are not making mistakes, or that their decisions are promoting their welfare. For example, present bias, optimistic overconfidence, and use of the availability heuristic can produce terrible mistakes and serious welfare losses, and this is so even if they have evolutionary foundations. There might well be evolutionary explanations for certain kinds of in-group favoritism, and also for certain male attitudes and actions toward women, and also for human mistreatment of and cruelty toward nonhuman animals. But those explanations would not justify anything at all. It is not clear that in Darwinia (a nation in which departures from perfect rationality have an evolutionary explanation), policymakers should behave very differently from Durkheimian policymakers (a nation in which departures from perfect rationality have a cultural explanation).

Important challenges like climate change require transformative policy responses. According to a growing public policy literature, such transformative responses typically require complex policy packages that bundle various individual policy instruments to complement each other, compensate transition losers, and create positive synergies. Nevertheless, while adding new instruments to a package can increase policy effectiveness, it comes at a price: increased policy design complexity. Increased complexity potentially leads to fundamental public misperceptions that undermine policy legitimacy and feasibility. Here, I argue that complex policy packages affect public opinion through a compensation, policy perception, and design complexity mechanism. To test this argument, this study assesses if citizens evaluate proposals for isolated climate policies related to food and mobility behaviors differently to complex policy packages. Employing a novel two-stage conjoint-experimental approach with 9115 respondents from the USA and Germany, the study shows that policy packaging increases citizens’ perceived policy effectiveness to reduce climate pollutants, but also perceived restrictions on citizens’ lifestyles. Moreover, increased design complexity can lead citizens to pay special attention to salient costly parts of policy packages. However, increased design complexity does not fundamentally reverse preferences. Through packaging desired and undesired policy instruments, policymakers can increase public support for transformative climate policies.

Cass Sunstein's contention that evolutionary explanations for behavioural economic phenomena are of limited relevance to public policy – and his support for soft paternalism – rests on his view that policymakers ought to be pursuing increases in some overarching social planning conception of welfare. In this reply to Sunstein, I argue that people have differing and multifarious desires in life, with the social planner's conception of welfare being, at best, perhaps only a partial consideration for most people. The phenomena that behavioural economists and psychologists have empirically observed may well facilitate people in the pursuit of their own desires in life. Consequently, paternalistic manipulation or coercion to save people from themselves is questionable in the behavioural public policy space, but government intervention is warranted when one party implicitly or explicitly uses these phenomena to exploit others.

Interventions that tackle ‘last mile’ behaviors in the form of improved choice architecture are fundamental to Behavioral Public Policy (BPP), yet far less attention is typically paid to the nature and design of underlying system conditions and infrastructures that support these interventions. However, inattention to broader conditions that impact participant engagement and intervention functionality, such as barriers to access that deter participation or perverse structural disincentives that reward undesirable behaviors, may not only limit the effectiveness of behavioral solutions but also miss opportunities to deliberately design underlying ‘plumbing’ – the choice infrastructure – in a way that improves overall system efficacy and equity. Using the illustrative case of civic policy in food licensure, this article describes how using a ‘SPACE’ model to address Standards, Process mechanics and policies, Accountability, Culture within systems, and Evaluative and iterative feedback can support the development of improved choice infrastructure, contributing to BPP problem-solving efforts by helping practitioners create system conditions that are more conducive to the success of behavioral solutions.

Self-control failure occurs when an individual experiences a conflict between immediate desires and longer-term goals, recognises psychological forces that hinder goal-directed action, tries to resist them but fails in the attempt. Behavioural economists often invoke assumptions about self-control failure to justify proposals for policy interventions. These arguments require workable methods for eliciting individuals’ goals and for verifying occurrences of self-control failure, but developing such methods confronts two problems. First, it is not clear that individuals’ goals are context-independent. Second, facing an actual conflict between a desire and a self-acknowledged goal, a person may consciously choose not to resist the desire, thinking that spontaneity is more important than self-control. We address these issues through an online survey that elicited individuals’ self-reported judgements about the relative importance of self-control and spontaneity in conflicts between enjoyment and health-related goals. To test for context-sensitivity, the judgement-elicitation questions were preceded by a memory recall task which directed participants’ attention either to the enjoyment of acting on desires or to the satisfaction of achieving goals. We found little evidence of context-sensitivity. In both treatments, however, judgements that favoured spontaneity were expressed with roughly the same frequency and strength as judgments that favoured self-control.

Personal data increasingly serve as inputs to public goods. Like other types of contributions to public goods, personal data are likely to be underprovided. We investigate whether classical remedies to underprovision are also applicable to personal data and whether the privacy-sensitive nature of personal data must be additionally accounted for. In a randomized field experiment on a public online education platform, we prompt users to complete their profiles with personal information. Compared to a control message, we find that making public benefits salient increases the number of personal data contributions significantly. This effect is even stronger when additionally emphasizing privacy protection, especially for sensitive information. Our results further suggest that emphasis on both public benefits and privacy protection attracts personal data from a more diverse set of contributors.

Behavioural science has been effectively used by policy makers in various domains, from health to savings. However, interventions that behavioural scientists typically employ to change behaviour have been at the centre of an ethical debate, given that they include elements of paternalism that have implications for people's freedom of choice. In the present article, we argue that this ethical debate could be resolved in the future through implementation and advancement of new technologies. We propose that several technologies which are currently available and are rapidly evolving (i.e., virtual and augmented reality, social robotics, gamification, self-quantification, and behavioural informatics) have a potential to be integrated with various behavioural interventions in a non-paternalistic way. More specifically, people would decide themselves which behaviours they want to change and select the technologies they want to use for this purpose, and the role of policy makers would be to develop transparent behavioural interventions for these technologies. In that sense, behavioural science would move from libertarian paternalism to liberalism, given that people would freely choose how they want to change, and policy makers would create technological interventions that make this change possible.

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.

On the one hand, default nudges are proven to strongly influence behavior. On the other hand, a number of consumer autonomy and welfare concerns have been raised that hinder public policy applications. Both nudge success and ethical concerns depend heavily on the design of defaults. We identify six taxonomic characteristics that matter to the ethical and the nudge success dimension. We review the default nudge literature (N = 61) and review ethical studies to assess both dimensions concerning the taxonomy. When designing a default, a choice architect inevitably makes a decision concerning the characteristics. Among others, the results show three main findings. (1) The initial choice architecture regularly imposes welfare losses and impedes consumer autonomy. Forced active choosing can mitigate both issues. (2) Empirical evidence suggests that transparent defaults are similarly effective as the non-transparent counterparts. (3) The framing of the choice in combination with a choice structuring default leads to greater nudge success and tends to involve the reflective decision-making patterns. Choice architects can trade-off nudge success for legitimacy but a design change may also benefit one without harming the other. We discuss further options of choice architects to legitimize a default.

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 this paper, I reflect on the implications that ultimatum and dictator game experiments might have for public policy and for the debates over egalitarianism. Experiments suggest that people are more inclined to redistribute when outcomes are influenced by luck than effort. This can create difficulties for public policy when people hold contrasting views over whether luck or effort determine outcomes. The results also appear to play into forms of luck egalitarianism. However, they may also be consistent with an alternative understanding of egalitarianism as the impulse to have rules that treat people equally.

In a previously published article, I reported some tests of prospect theory's reflection effect over outcomes defined by money and life years gained from treatment. Those results suggested qualified support for the reflection effect over money outcomes and strong support over longevity outcomes. This article reruns those tests while accounting for the intensity of individual risk attitudes, and, overall, show consistency with the reflection effect. However, I argue that these results do not necessarily offer support for the explanatory power of prospect theory. Rather, the results may be driven by evolved responses to circumstances that provoke perceptions of scarcity and abundance. Therefore, from an ecological perspective, behavioral patterns such as those that are consistent with the reflection effect, which, by extension, tend to be considered as erroneous or biased by most behavioral economists because they conflict with the postulates of rational choice theory, may not be unreasonable. Recognizing as such is important when considering how behavioral insights ought to inform public policy design and implementation.

The ultimatum and dictator games were developed to help identify the fundamental motivators of human behavior, typically by asking participants to share windfall endowments with other persons. In the ultimatum game, a common observation is that proposers offer, and responders refuse to accept, a much larger share of the endowment than is predicted by rational choice theory. However, in the real world, windfalls are rare: money is usually earned. I report here a small study aimed at testing how participants react to an ultimatum game after they have earned their endowments by either building a Lego model or spending some time sorting out screws by their length. I find that the shares that proposers offer and responders accept are significantly lower than that typically observed with windfall money, an observation that is intensified when the task undertaken to earn the endowment is generally less enjoyable and thus perhaps more effortful (i.e., screw sorting compared to Lego building). I suggest, therefore, that considerations of effort-based desert are often important drivers behind individual decision-making, and that laboratory experiments, if intended to inform public policy design and implementation, ought to mirror the broad characteristics of the realities that people face.

A concern that people ought to be given what they deserve, in both positive and negative senses, lies deep within the human psyche. Views on the level of reward or punishment that a person deserves for their actions will differ across persons, places, and time, but, I argue in this article, depend substantively upon some combination of intentions and outcomes. Using these characteristics, I propose a taxonomy of actions, ordered from most to least blameworthy, with, for example, it being suggested that for any particular level of harm an intentional yet unrealized harm is more blameworthy than an unintentional yet realized harm (a similar taxonomy can be developed for the positive domain of praiseworthy actions). The taxonomy is focused upon people's actions toward others, but I finish the article with a discussion of desert in relation to people's intentions toward themselves. Ultimately, I contend that the strength and sustainability of public sector services and welfare systems, not to mention our private relationships, rely upon the recognition that desert underpins our notion of justice.

Loot boxes provide randomized rewards in video games; their purchase is linked to disordered gambling and they are present in approximately half of UK video games. The relative novelty of loot boxes means that regulators and policymakers in various jurisdictions are still deciding how to regulate them. The People's Republic of China (PRC) is the first, and presently only, jurisdiction to legally require companies to disclose the probabilities of obtaining randomized loot box rewards – an approach that is also favored by the industry as self-regulation. This study is the first to assess paid loot box prevalence in the PRC and companies’ discretionary interpretations of probability disclosure regulations. Loot boxes were found in 91 of the 100 highest-grossing PRC iPhone games. Of games deemed suitable for children aged 12+, 90.5% contained loot boxes. Probability disclosures could not be found for 4.4% of games containing loot boxes. Disclosures were implemented through various methods both in-game and on the games’ official websites; however, consistent with the concept of ‘sludge,’ only 5.5% used the most prominent format of automatically displaying the probabilities on the in-game loot box purchase page. Loot box probability disclosures should be uniform and visually prominent to best help inform consumers.

When governments and healthcare providers offer people cash rewards for weight loss, an assumption is that cash rewards are versatile, working equally well for everyone – for example, for all genders. No research to date has tested for gender difference in response to financial incentives for weight loss. We show in an randomized controlled trial (RCT) (n = 472) that cash incentives for weight loss only worked for males. The RCT consisted of a 3-month, self-administered online weight loss program. Offering a US$150 incentive for a 5% weight loss more than tripled the proportion of males who were successful, compared with a no-incentive Control arm (20.9% vs. 5.9%). On average, males in the incentive arm lost 2.4% of weight over 3 months, compared with 0.9% in the Control arm. The same incentive had no such effect on females: The average weight loss in the incentive arm was not significantly different than in the Control (1.03% and 1.44%, respectively), nor was the proportion of participants meeting the 5% weight loss goal (8.6% and 8.7%, respectively). This study shows that males respond better than females to financial incentives for weight loss.

Despite widespread recognition that behavioral public policy (BPP) needs to move beyond nudging if the field is to achieve more significant impact, problem-solving approaches remain optimized to achieve tactical success and are evaluated by short-term metrics with the assumption of stable systems. As a result, current methodologies may contribute to the development of solutions that appear well formed but become ‘brittle’ in the face of more complex contexts if they fail to consider important contextual cues, broader system forces, and emergent conditions, which can take three distinct forms: contextual, systemic, and anticipatory brittleness. The Covid-19 pandemic and vaccination rollout present an opportunity to identify and correct interventional brittleness with a new methodological approach – strategic BPP (SBPP) – that can inform the creation of more resilient solutions by embracing more diverse forms of evidence and applied foresight, designing interventions within ecosystems, and iteratively developing solutions. To advance the case for adopting a SBPP and ‘roughly right’ modes of inquiry, we use the Covid-19 vaccination rollout to define a new methodological roadmap, while also acknowledging that taking a more strategic approach may challenge current BPP norms.

Nudging has become a well-known policy practice. Recently, ‘boosting’ has been suggested as an alternative to nudging. In contrast to nudges, boosts aim to empower individuals to exert their own agency to make decisions. This article is one of the first to compare a nudging and a boosting intervention, and it does so in a critical field setting: hand hygiene compliance of hospital nurses. During a 4-week quasi-experiment, we tested the effect of a reframing nudge and a risk literacy boost on hand hygiene compliance in three hospital wards. The results show that nudging and boosting were both effective interventions to improve hand hygiene compliance. A tentative finding is that, while the nudge had a stronger immediate effect, the boost effect remained stable for a week, even after the removal of the intervention. We conclude that, besides nudging, researchers and policymakers may consider boosting when they seek to implement or test behavioral interventions in domains such as healthcare.

Nudges based on social norms (norm-nudges) can be compelling behavioral interventions compared with traditional interventions such as taxes and regulations, but they do not work in all circumstances. We tested two empirical norm-nudge frames in an online experiment on taking measures for flood preparedness with large samples of homeowners (N = 1805) in two European countries, to evaluate the possible interactions between norm-nudge effectiveness, individual characteristics, and intercultural differences. We contrasted these norm-nudge treatments with a control and norm-focusing treatment by asking respondents to express their beliefs about what other respondents would do before making a decision relevant to their own payoff. We find no evidence of a treatment effect, suggesting that our social norm-nudges do not affect flood preparedness in the context of a flood risk investment game.

Behavioral scientists have begun to research ‘sludge,’ excessive frictions that make it harder for people to do what they want to do. Friction is also an important concept in transaction-cost economics. Nevertheless, sludge has been discussed without explicit referral to transaction costs. Several questions arise from this observation. Is the analogy to friction used differently in both literatures? If so, what are the key differences? If not, should we develop the concept of sludge when the well-established literature on transaction costs already exists? This conceptual article shows that sludge and transaction costs are related, but distinct, concepts, and that the literature on sludge can benefit from incorporating elements from transaction-cost research. For example, we suggest defining sludge as aspects of the choice architecture that lead to the experience of costs, organize sludges using a typology inspired by the transaction-cost literature, highlight specificity, uncertainty, and frequency as important determinants of the ‘sludginess’ of choice architecture, and show that sludge audits can be conducted using methods developed in the transaction-cost literature.