As nudge interventions have become more popular, academic research is developing that assesses to what extent these interventions are effective. My paper contributes to this stream of research: collating and synthesising evidence on the effectiveness of nudge interventions that aim to increase consumer search and switching in retail financial markets. Following a systematic search strategy, I identify 35 relevant papers, including qualitative studies, laboratory experiments, field experiments and ex post analyses, covering a range of retail financial products and different types of nudges. The review results in two main contributions. First, it demonstrates that different study designs serve different purposes in evidence accumulation. Second, based on over 400 estimates extracted from these papers, it establishes that the currently available evidence shows that nudges increase consumer search and switching in retail financial markets by 2–3 percentage points on average. Structural nudges that change the choice architecture more profoundly have a higher impact on search and switching than nudges that provide, simplify or highlight information. While nudge interventions may be efficient on a cost–benefit basis and can lead to a large increase in relative terms (e.g. doubling switching rates from 1% to 2%), regulators cannot expect them to significantly alter consumer behaviour.

The serial rapist model claims that a small number of intentional, repeat offenders are responsible for the majority of sexual assaults on college campuses. The model has formed the dominant argument for some of the most popular forms of campus intervention programs and is cited by high profile advocates and policymakers. Despite enthusiasm for the serial rapist model, it is not empirically well-supported and is contradicted by recent robust data. In this article, we ask: why does the serial rapist model have such broad and enduring appeal? In two US-based samples, one convenience and one representative, we find that people's endorsement of the serial rapist model correlates with worldviews that cohere around ideas of a just and good status quo, and a preference for simple stories. Specifically, we find a positive relationship between endorsement of the serial rapist model and belief in a just world, system justification, social dominance orientation, need for closure and essentialism.

In Indonesia, as in other countries, a large proportion of tax returns are filed at the last minute. In a population-wide randomised controlled trial (n = 11,157,069), we evaluated the impact of behavioural email prompts on the proportion of annual tax returns filed at least two weeks before the deadline; and overall filing rate. In two control conditions, taxpayers either received no email or an email used in prior years, emphasising regulatory information. The five treatments informed by behavioural science were (1) a simplified version of the existing email, emphasising early filing; (2) the simplified version with additional guidance on filing taxes; (3) the simplified version with a planning prompt and option to sign up for email reminders; (4) a version combining treatments 1, 2 and 3; and (5) an email appealing to national pride. Compared to the no-email control, all emails led to a statistically significant increase in early and overall filing rates. The planning email (3) was the most effective, increasing early filling from 34.9% to 37% (b 2.07 percentage points (pp), p < 0.001, 95% confidence interval (CI) 1.97–2.17pp), and overall filing from 65.6% to 66.7% (b 1.10pp, p < 0.001, 95% CI 0.99–1.19pp).

Behavioural science has found growing application in applied public policy settings, offering a vast literature to bring to bear on apparent cognitive errors. The potential, however, is not without peril. Policymakers and scholars may draw unwarranted confidence that successful behavioural interventions from elsewhere will replicate in their institutional settings. In this research, I partner with Minneapolis Public Housing and use a design-based approach to identify interventions that can reduce eviction actions. This study presents three vignettes that demonstrate and categorize the mistakes behavioural science can make when it fails to understand how formal and informal institutional features influence decision-making. But, in integrating methods and theories from the design sciences, public policy and public administration, we have the potential to create behavioural interventions that fit the social context.

A substantial experimental literature in behavioral economics and psychology finds that individuals rely on heuristics and cognitive biases when they make decisions. These heuristics and biases impact the choices of individuals from all walks of life, including police officers entrusted with the power to enforce laws. Individuals act within an institutional context. We examine how the institutions that structure American policing interact with the heuristics and biases of individual police officers. We then suggest institutional changes that may result in better performance from boundedly rational police officers.

While behavioral public policy remains underutilized in rich countries relative to its potential impact, the required infrastructure for diagnosing behavioral bottlenecks and the autonomy to act on those diagnoses are even less common in developing countries. At the World Bank, the Mind, Behavior, and Development Unit (eMBeD) aims to promote the systematic use of behaviorally informed tools in development policies and projects, institutionalize the use of behavioral science in development organizations and governments, provide evidence on scaled and sustainable behavioral solutions, and generate more and better behavioral data. By focusing on thorough diagnosis and ongoing adaptation, we aim to create impactful, behaviorally informed interventions in complex, resource-constrained settings. While Sanders, Snijders and Hallsworth (2018) raise valuable points about the implications for impactful behavioral public policy, for those working in developing countries, issues of replication and scale come with unique contextual challenges.

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.

In The Rhetoric of Reaction, published in 1991, Albert Hirschman identified three standard objections to reform proposals: perversity, futility and jeopardy. In Hirschman's account, these objections define reactionary rhetoric. A proposal would be “perverse” if it would aggravate the very problem it is meant to solve; it would be “futile” if it would not even dent the problem; it would produce “jeopardy” if it would endanger some other goal or value (such as liberty or economic growth). The rhetoric of reaction comes from both left and right, though in Hirschman's account, it is a special favorite of the right. In recent years, the perversity, futility and jeopardy theses have often been invoked to challenge reforms, including nudges. While the three theses are sometimes supported by the evidence, they are often evidence-free speculations, confirming Hirschman's suggestion that the rhetoric of reaction has “a certain elementary sophistication and paradoxical quality that carry conviction for those who are in search of instant insights and utter certainties.”

The effectiveness and uptake of financial incentives can differ substantially between reward- and deposit-based incentives. Therefore, it is unclear to whom and how different incentives should be assigned. In this study, the effect of different modes of assigning reward- and deposit-based financial incentives on effort is explored in a two-session experiment. First, students’ (n = 228, recruited online) discounting, loss aversion and willingness to pay a deposit were elicited. Second, an incentivized real-effort task was completed (n = 171, 25% drop-out). Two modes of assigning reward- or deposit-based financial incentives were compared: random assignment and ‘nudged’ assignment – assignment based on respondent characteristics allowing opting out. Our results show that respondents receiving nudged assignment earned more and persisted longer on the real-effort task than respondents randomly assigned to incentives. We find no differences in effectiveness between reward-based or deposit-based incentives. Overall, 39% of respondents in the nudged assignment mode followed-up the advice to take deposit-based incentives. The effect of deposit-based incentives was larger for the respondents who followed-up the advice than for respondents that randomly received deposit-based incentives. Overall, these findings suggest that nudged assignment may increase incentives’ effect on effort. Future work should extend this approach to other contexts (e.g., behaviour change).

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.

The relevant literature notes a lack of applications relative to the theoretical impact of prospect theory. In this paper, I provide a brief review of this literature aimed at policymakers before developing an idea for lottery-based government subsidy policies. I consider the general conditions under which such policies could be effective in (1) increasing the performance of desired behaviours and (2) saving governments money. I provide two examples of current Canadian subsidies that I argue could be improved with the addition of a lottery option.

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.

Frijters et al. make a powerful and lucid case for a top-down approach to government, in which the maximization of wellbeing should be the ultimate goal. I argue, by contrast, for a bottom-up approach: that the variety of goals, plans, norms and rules that govern our lives should be the starting point for political discussion. From this standpoint, the goal of individual and collective decision-making of all kinds is the reconciliation of conflicting objectives and priorities on a piecemeal basis. The distinction between top-down and bottom-up approaches in political decision-making parallels debates between ‘foundationalists’ and ‘coherentists’ in epistemology.

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.

A reduction in the demand for meat and particularly red meat has the potential to significantly enhance the sustainability and health of many people's diets. In the current work, I examine situational predictors of meat consumption in nationally representative nutrition surveys from three Western European countries: Switzerland, France and the Netherlands. More specifically, I examine whether the situational factors – the meal type, the day of the week and the location of the food consumption occasion – are predictive of whether meat and red meat are consumed. The results indicate that all three factors are linked to meat and red meat consumption with the patterns varying substantially across the different case study countries and in some cases also the gender of the consumer. The results emphasise the value of mapping situational correlates to inform situated interventions aimed at influencing meat consumption, while also highlighting important differences across both cultures and people.

A multi-item questionnaire concerning lay people's attitudes toward organ procurement without consent from executed prisoners was given to several hundred respondents. The items ranged from all-out condemnation (“It is tantamount to murder”) to enthusiasm (“It is great to have this organ supply”). Overall, we found two guiding principles upheld by most respondents: (1) Convicts have as much a right to their bodies and organs as other people, so the practice should be judged by the same standards as those that guide organ procurement from any donor. Procuring organs without consent is wrong. (2) Benefiting from those organs should be held to more lenient standards than are demanded for their procurement. So, benefitting from these ill-gotten organs should be tolerated.