Gambling is considered a public health issue by many researchers, similarly to alcohol or obesity. Statistical risk warnings on gambling products can be considered a public health intervention that encourages safer gambling while preserving freedom of consumer choice. Statistical risk warnings may be useful to gamblers, given that net gambling losses are the primary driver of harm and that gambling products vary greatly in the degree to which they facilitate losses. However, there is some doubt as to whether statistical risk warnings are, in their current form, effective at reducing gambling harm. Here, we consider current applications and evidence, discuss product-specific issues around a range of gambling products and suggest future directions. Our primary recommendation is that current statistical risk warnings can be improved and also applied to a wider range of gambling products. Such an approach should help consumers to make more informed judgements and potentially encourage gambling operators to compete more directly on the relative ‘price’ of gambling products.

Gender-neutral bathrooms are usually framed as an accommodation for trans and other gender-nonconforming individuals. In this paper, we show that the benefits of gender-neutral bathrooms are much broader. First, our simulations show that gender-neutral bathrooms reduce average waiting times: while waiting times for women go down invariably, waiting times for men either go down or slightly increase depending on usage intensity, occupancy-time differentials and the presence of urinals. Second, our result can be turned on its head: firms have an opportunity to reduce the number of facilities and cut costs by making them all gender-neutral without increasing waiting times. These observations can be used to reframe the gender-neutral bathrooms debate so that they appeal to a larger constituency, cutting across the usual dividing lines in the ‘bathroom wars’. Finally, there are improved designs and behavioural strategies that can help overcome resistance. We explore what strategies can be invoked to mitigate the objections that gender-neutral bathrooms (1) are unsafe, (2) elicit discomfort and (3) are unhygienic.

With a linear public goods game played in six different variants, this article studies two channels that might moderate social dilemmas and increase cooperation without using pecuniary incentives: moral framing and shaming. We find that cooperation is increased when noncontributing to a public good is framed as morally debatable and socially harmful tax avoidance, while the mere description of a tax context has no effect. However, without social sanctions in place, cooperation quickly deteriorates due to social contagion. We find ‘shaming’ free-riders by disclosing their misdemeanor to act as a strong social sanction, irrespective of the context in which it is applied. Moralizing tax avoidance significantly reinforces shaming, compared with a simple tax context.

In this study, we investigated how people evaluate behavioral interventions (BIs) that are targeted at themselves, aiming to promote their own health and wellbeing. We compared the impact on people's assessments of the acceptability of using BIs to change their own behavior of: the transparency of the BI (transparent or opaque); the designer of the BI (researchers, government policy-makers, advertisers); and three types of arguments regarding their efficacy (positive, positive + negative, negative). Our target BIs were actual interventions that have been used in a range of policy domains (diet, exercise, alcohol consumption, smoking, personal finances). We found that transparent BIs were considered more acceptable than opaque BIs. On average, all BIs were considered acceptable for changing participants’ own behavior, except for the opaque BI in the finance context; there was differential acceptability of BIs across contexts, with finance clearly least acceptable. However, the perceived effectiveness of the BIs was at least as influential a predictor of acceptability ratings as the ease of identification of the behavior change mechanism across the five contexts. Furthermore, effectiveness was partially mediated by desire to change, suggesting that people do think BIs make them better off, ‘as judged by themselves’.

Nudges – light-touch interventions aimed to help people achieve socially desirable outcomes – can take place without individuals being aware of them. It would seem to be ethically superior to tell individuals that they are being nudged, encouraging them to be aware of the reasons for the official interest in their behaviours. Aided by internal reflection, individuals may make informed choices whether to go along with officially-preferred options or not. In general, this paper adopts this line of argument, justifying self-awareness from the liberal belief in autonomy of the person. However, awareness and/or reflection are not always necessarily ethically superior to passivity, as in cases where manipulation is also present with information provision, when there is framing of deliberative exercises, and where there is harm done to others due to reflectively-driven actions. Most of the time self-awareness is to be preferred, but not always.

Prior research in the behavioral sciences has demonstrated that reminders can be an effective tool for encouraging health-related behavior changes. This article extends that literature by reporting the outcome of a randomized controlled trial of mailed vaccination reminders. In addition to making a substantive contribution regarding the efficacy of mailed reminders, this article also makes a methodological contribution: it illustrates how researchers can study the causal impact of an intervention even when a pure parallel trial is not possible. In this study, the Louisiana Department of Health sent postcard reminders regarding four recommended vaccinations (influenza, tetanus, shingles and pneumonia) to 208,867 senior residents of Louisiana. We used block randomization and a stepped wedge design to assess the efficacy of the intervention. Individuals were blocked by their prior vaccine record and randomized to receive the postcard in one of four consecutive months (October–January). The reminder postcard had an overall positive effect on vaccination rates. The statistically significant and substantively small increase in overall vaccination rates was driven by participants who received the postcard reminder early in the intervention period.

Rapid and comprehensive social change is required to mitigate pressing environmental issues such as climate change. Social tipping interventions have been proposed as a policy tool for creating this kind of change. Social tipping means that a small minority committed to a target behaviour can create a self-reinforcing dynamic, which establishes the target behaviour as a social norm. The possibility of achieving the large-scale diffusion of pro-environmental norms and related behaviours with an intervention delimited in size and time is tempting. Yet, the canonical model of tipping, the coordination game, may evoke overly optimistic expectations regarding the potential of tipping, due to the underlying assumption of homogenous preferences. Relaxing this assumption, we devise a threshold model of tipping pro-environmental norm diffusion. The model suggests that depending on the distribution of social preferences in a population, and the individual cost of adopting a given pro-environmental behaviour, the same intervention can activate tipping, have little effect, or produce a backlash. Favourable to tip pro-environmental norms are widespread advantageous inequity aversion and low adoption costs. Adverse are widespread self-regarding preferences or disadvantageous inequity aversion, and high costs. We discuss the policy implications of these findings and suggest suitable intervention strategies for different contexts.

Millions of Europeans use online platforms with almost blind trust that the platforms operate in the interests of the consumer. However, the presentation of search results, transparency about contractual parties and the publication of user reviews that contribute to the value of online platforms in Europe's Single Digital Market also pose significant risks regarding consumer protection and market competition. The current study investigates how enhanced information transparency in online platforms might affect consumers’ trust in online activities and choice behaviour. Following an exploratory qualitative study, three online discrete-choice experiments were conducted with representative samples of 1200 respondents in each of four countries: Germany, Poland, Spain and the UK. The objective of the experiments was to test whether increased transparency in the presentation of online search information, details of contractual entities and the implications for consumer protection and user reviews and ratings would affect consumers’ choices. The results show that increased online transparency increases the probability of product selection. A comparison across the four countries found that the similarities in responses to online transparency were far greater than the differences. The findings are discussed in relation to the biases and heuristics identified in behavioural science. In conclusion, recommendations are made to increase online transparency, which the empirical evidence of this study shows would benefit both users and platform operators.

Two concepts shaped and continue to shape the discussion on the limits of a liberal and democratic state. First, Mill's harm principle, according to which the fundamental justification for a state exercising power over individuals is to prevent harm being done to others. Second, the distinction between the public sphere, where liberal democracies can intervene, and the private sphere, where individuals are, in principle, free to do as they like. I argue that both concepts have to be revisited in the context of today's ‘ultra-processed’ world, in which sophisticated technologies and highly engineered products reach deep into the private sphere, exploiting human psychology and jeopardizing citizens’ health and welfare in the interest of maximizing profit. In this ultra-processed world, where the distinction between the public and the private spheres is blurred, systemic interventions such as regulation and taxation, often criticized as paternalistic, are necessary to minimize harm. However, they must be complemented by interventions informed by behavioural science that modify and guide individual behaviours. Beyond the soft paternalism of nudging, people can be empowered to self-nudge – a non-paternalistic approach that enables them to design and structure their own decision environments and choice architectures as they see fit.

We assess the effects of the Crianza Positiva text and audio e-messaging program on caregiver–child language interaction patterns. The program is a six-month-long intervention for families with children aged 0–2 aimed at strengthening parental competences. Its design exploits behavioral tools such as reminders, suggestions of action, and messages of encouragement to reinforce and sustain positive parenting practices. Families in 24 early childhood centers in Uruguay that completed an eight-week workshop were randomized into receiving or not receiving mobile messages. After the program, we videotaped 10-minute sessions of free play between the caregiver and the child, and decoded language patterns using automated techniques. The intervention was successful at improving the quality of parental vocalizations, as measured by the parent's pitch range. We also found suggestive evidence of increases in the duration of adult vocalizations. The results are consistent with more frequent parental self-reported involvement in reading, telling stories, and describing things to the child. Regarding the child, we find a nonrobust decrease in the duration of vocalizations, which we attribute to a crowding-out effect by the caregiver in the context of a fixed 10-minute suggested activity and a more proactive parental role.

Toilet ownership in India has grown in recent years, but open defecation can persist even when rural households own latrines. There are at least two pathways through which social norms inhibit the use of toilets in rural India: (1) beliefs/expectations that others do not use toilets or latrines or find open defecation unacceptable; and (2) beliefs about ritual notions of purity that dissociate latrines from cleanliness. A survey in Uttar Pradesh, India, finds a positive correlation between latrine use and social norms at baseline. To confront these, an information campaign was piloted to test the effectiveness of rebranding latrine use and promoting positive social norms. The intervention targeted mental models by rebranding latrine use and associating it with cleanliness, and it made information about growing latrine use among latrine owners more salient. Following the intervention, open defecation practices went down across all treatment households, with the average latrine use score in treatment villages increasing by up to 11% relative to baseline. Large improvements were also observed in pro-latrine beliefs. This suggests that low-cost information campaigns can effectively improve pro-latrine beliefs and practices, as well as shift perceptions of why many people still find open defecation acceptable. Measuring social norms as described can help diagnose barriers to reducing open defecation, contribute to the quality of large-scale surveys and make development interventions more sustainable.

Four experiments examine the impact of a firm deciding to no longer pay salaries for executives versus employees on consumer behavior, particularly in the context of the COVID-19 pandemic. Study 1 explores the effect of announcing either pay cessations or continued pay for either CEO or employees, and shows that firms’ commitment to maintaining employee pay leads to the most positive consumer reactions. Study 2 examines the effects of simultaneously announcing employee and CEO pay cessations: consumers respond most positively to firms prioritizing employee pay, regardless of their strategy for CEO pay. Moreover, these positive perceptions are mediated by perceptions of financial pain to employees, more than perceptions of CEO-to-worker pay ratio fairness. Study 3, using an incentive-compatible design, shows that firms’ commitment to paying employees their full wages matters more to consumers than cuts to executive pay, even when those executive pay cuts lead to a lower CEO-to-worker pay ratio. Study 4 tests our account in a non-COVID-19 context, and shows that consumers continue to react favorably to firms that maintain employee pay, but when loss is less salient, consumers prioritize cutting CEO pay and lowering the CEO-to-worker pay ratio. We discuss the implications of our results for firms and policymakers during economic crises.

Regulators require lenders to display a subset of credit card features in summary tables before customers finalize a credit card choice. Some jurisdictions require some features to be displayed more prominently than others to help ensure that consumers are made aware of them. This approach could lead to untoward effects on choice, such that relevant but nonprominent product features do not factor in as significantly. To test this possibility, we instructed a random sample of 1615 adults to choose between two hypothetical credit cards whose features were shown side by side in tables. The sample was instructed to select the card that would result in the lowest financial charges, given a hypothetical scenario. Critically, we randomly varied whether the annual interest rates and fees were made visually salient by making one, both, or neither brighter than other features. The findings show that even among credit-savvy individuals, choice tends strongly toward the product that outperforms the other on a salient feature. As a result, we encourage regulators to consider not only whether a key feature should be made more salient, but also the guidelines regarding when a key feature should be displayed prominently during credit card acquisition.

We examine the causes and policy implications of strategic (willful) ignorance of risk as an excuse to over-engage in risky health behavior. In an experiment on Copenhagen adults, we allow subjects to choose whether to learn the calorie content of a meal before consuming it and then measure their subsequent calorie intake. Consistent with previous studies, we find strong evidence of strategic ignorance: 46% of subjects choose to ignore calorie information, and these subjects subsequently consume more calories on average than they would have had they been informed. While previous studies have focused on self-control as the motivating factor for strategic ignorance of calorie information, we find that ignorance in our study is instead motivated by optimal expectations – subjects choose ignorance so that they can downplay the probability of their preferred meal being high-calorie. We discuss how the motivation matters to policy. Further, we find that the prevalence of strategic ignorance largely negates the effects of calorie information provision: on average, subjects who have the option to ignore calorie information consume the same number of calories as subjects who are provided no information.

Public policies often involve “norm nudging”, the use of norm information to steer individual behavior in a prosocial direction. Analysis of social norm messaging often concentrates on the outcome measure: the potential change in behavior. The cognitive and psychological processes that underlie individuals’ response to norm information, especially the inferences they draw, are usually overlooked. This knowledge gap may lead to adverse consequences, such as messages backfiring. To (factually) justify norm nudging interventions, it is essential that policymakers understand the complex mechanisms that link context, social expectations and preferences, and how the interpretation of different types of messages affects behavior.

Given the rates of transmission of COVID-19, relying only on manual contact tracing might be infeasible to control the epidemic without sustained costly lockdowns or rapid vaccination efforts. In the first study of its kind in Latin America, we find through a phone survey of a nationally representative sample of ten countries that an opt-out regime (automatic installation) increases self-reported intention to accept a contact tracing app with exposure notification by 22 percentage points compared to an opt-in regime (voluntary installation). This effect is triple the size and of opposite sign of the effect found in Europe and the United States, potentially due to lower concerns regarding privacy and lower levels of interpersonal trust. We see that an opt-out regime is more effective in increasing willingness to accept for those who do not trust the government or do not use their smartphones for financial transactions. The local severity of the pandemic does not affect our results, but feeling personally at risk increases intent to accept such apps in general. These results can shed light on the use of default options not only for contact tracing apps but in public health overall in the context of a pandemic in Latin America.

A recent development within nudge theory is the concept of sludge, which imposes frictions on decision-making. Nascent literature adopts a normative interpretation of sludge: nudge good, sludge bad. However, this normative interpretation leaves much to be desired. A clear definition and treatment of sludge remains absent from this literature, as is a complete understanding of ‘frictions’. Furthermore, the relationship between nudges and sludges is unclear. This paper proposes the concept of nudge/sludge symmetry in an attempt to advance the conceptual understanding of sludge. Building from the definition of a nudge, three types of friction permissible under nudge theory are identified: hedonic, social and obscurant. Sludge is then positioned, in terms of frictions, relative to nudge: nudges decrease relative frictions, sludges increase relative frictions. A consequence of this proposition is nudge/sludge symmetry – where a nudge decreases the frictions associated with a specific option, sludge is simultaneously imposed on all other options available to a decision-maker. Nudge/sludge symmetry subsequently challenges the normative interpretation of sludge, and so a new framework drawing on the literature on nudges in the private sector is offered, with the choice architect placed at the centre. This new approach to sludge and emphasis on the role of the choice architect, in turn, reaffirms the importance of transparency in public policy interventions.

Identifying influential people within a community to involve in a program is an important strategy of behavioral interventions. How to efficiently identify the most effective individuals is an outstanding question. This paper compares two common strategies: consulting ‘network insiders’ versus ‘network observers’ who have knowledge of but who do not directly participate in the community. Compared to aggregating information from all insiders, asking relatively fewer observers is more cost-effective, but may come at a cost of accuracy. We use data from a large-scale field experiment demonstrating that central students, identified through the aggregated nominations of students (insiders), reduced peer conflict in 56 middle schools. Teachers (observers) also identified students they saw as influential. We compare the causal effect of the two types of nominated students on peer outcomes and the differences between the two types of students. In contrast to the prosocial effects of central students on peer conflict, teacher nominees have no, or even antisocial, influence on their peers’ behaviors. Teachers (observers) generally nominated students with traits salient to them, suggesting that observer roles may systematically bias their perception. We discuss strategies for improving observers’ ability to identify influential individuals in a network as leverage for behavioral change.

In this article, the confidence that has been placed in hard and, in particular, soft paternalistic measures in the field of behavioural public policy is questioned. The four purported limitations of human reasoning – i.e. limited imagination, willpower, objectivity and technical ability – are considered, but ultimately it is concluded that these are insufficient justifications for paternalistic intervention, for two principal-related reasons. First, it is impossible for a policy maker to discern what people desire for their own lives, and second, so long as they are not harming others, people ought to be free to pursue their own desires. The vision for the future of behavioural public policy proposed here is thus consistent with classical liberal, and in particular, Millian thought: i.e. aim to educate people on the pros and cons of their actions and inactions so that they are better equipped to live the lives they wish to lead but do not interfere directly in guiding them towards any particular end.