Naturalistic monitoring tools provide detailed information about people's behaviours and experiences in everyday life. Most naturalistic monitoring research has focused on measuring subjective well-being. This paper discusses how naturalistic monitoring can inform behavioural public policy-making by providing detailed information about everyday decisions and the choice architecture in which these decisions are made. We describe how the Day Reconstruction Method (DRM) – a naturalistic monitoring tool popular in the subjective well-being literature – can be used to: (i) improve ecological validity of behavioural economics; (ii) provide mechanistic evidence of the everyday workings of behavioural interventions; and (iii) help us to better understand people's true preferences. We believe that DRM data on everyday life have great potential to support the design and evaluation of behavioural policies.

Local public managers increasingly use behavioral policy instruments to influence the behavior of citizens. However, despite their increased reliance on these instruments, there is little evidence on why local public manager would prefer behavioral instruments over classic stick, carrot or sermon-type instruments. We conduct a mixed-methods study, combining a stated-preference survey and two focus groups, to examine whether senior local public managers (directors and deputy directors) in Flanders prefer behavioral policy instruments over classic stick, carrot and sermon-type instruments, and explore whether their trust in citizens (perceptions of citizen’s ability, benevolence and integrity) affects these preferences for policy instruments. The results indicate that in some policy areas, such as health, public nuisance and road safety, public managers appear more willing to use behavioral policy instruments than classic sticks and carrots, but not sermons. Furthermore, we find that public managers’ trust in citizens does not appear to significantly affect their preferences for policy instruments, but that political and economic motives do play a role in their preferences for behavioral policy instruments. Finally, the results also indicate that the simultaneous use of behavioral and classic policy instruments (packaging) can help mediate the perceived risks of citizens’ non-compliance with behavioral policy instruments.

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.

Behavioural public policy analysts have examined cases of individuals’ failures of reason or judgement to attain their ends and have used these to justify ‘means’ paternalism: a form of government intervention that tries to save individuals from the consequences of those reasoning failures and to enable them better to achieve those ends. This has been challenged on a number of grounds, including too great a focus on choice-preserving interventions such as nudges, the privileging of future preferences over current ones and the possibility of state failures as damaging to individual well-being as the original reasoning failure. This paper summarizes the principal arguments in favour of means paternalism and then addresses these challenges.

We asked individuals about their willingness to pay (WTP) either: (1) for a mandate requiring restaurants to post calorie information on their menus; or (2) to avoid such a mandate. On average, more people were in in favor of the mandate and were willing to pay four times more than those who were against it, thereby leading to a Kaldor–Hicks improvement from this policy. To ensure robustness, we tested the impact of providing three types of information during individuals’ WTP determinations: (1) visual examples of the proposed calorie labels; (2) data on their effectiveness at the individual level; and (3) data on their wider social and economic benefits. For those in favor, providing a simple visual of the label had no impact on WTP. Data on the individual effectiveness of the labels increased the WTP, while evidence on broader obesity reduction and economic benefits reduced it. For opponents, WTP did not change with provision of additional information except when provided with information on social and economic benefits. Under this condition, the opponents increased their WTP 12-fold to avoid a mandate of this policy. Finally, we measured individual well-being under this policy and found directionally similar results, confirming a net improvement in aggregate welfare. Our results suggest that messaging that focuses on private benefits (providing calorie information so that individuals can effectively choose to reduce excessive caloric consumption) rather than wider public benefits (reduction in overall health-related costs and obesity) is more likely to be effective.

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.

The COVID-19 pandemic has forced governments around the world into drastic measures without the normal evidence base or analyses of consequences. We present a quantitative model that can be used to rapidly assess the introduction and interaction of nonpharmaceutical infection prevention measures (NPI) both in rapid a priori predictions and in real-world a posteriori evaluations. Two of the most popular NPIs are imposing minimum physical interpersonal distancing and the use of face coverings. The success of both measures is highly dependent on the behavior of the public. However, there is very little published information about the interactions between distance, mask wearing, and the behavioral adaptations that they are likely to generate. We explore the relation between these two fundamental NPIs and the behavioral responses that they may induce, considering both risk compensation and social norms enhancement. At present, we do not have the necessary information to parameterize our model to a sufficient degree to generate quantitative, immediately applicable, advice, but we explore a vast parameter space and illustrate how the consequences of such measures can range from highly beneficial to paradoxically harmful in plausible real situations.

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.”

Kahneman’s criticism of neoclassical rationality was central to his research programme. He argued that rationality understood as temporal consistency among preferences and beliefs is inapt as a descriptive and prescriptive standard of decision-making. Descriptively, consistency ignores high decision costs and biases, such as framing effects. Prescriptively, it is problematic since it neglects the processual nature of choice and the crucial role of regret. Instead, Kahneman argued in favour of using reasonableness as a standard, though he did not fully develop the concept in his work.

The current state of the art in field experiments does not give me any confidence that we should be assuming that we have anything worth scaling, assuming we really care about the expected welfare of those about to receive the instant intervention. At the very least, we should be honest and explicit about the need for strong priors about the welfare effects of changes in averages of observables to warrant scaling. What we need is a healthy dose of theory and the implied econometrics.

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.

Viewed from both an ethical and practical perspective, it is clearly desirable that public sector allocative and regulatory decisions should, so far as possible, reflect the preferences of individual members of society. It is therefore hardly surprising that, in appraising proposed safety improvements, public sector bodies have displayed an increasing tendency to estimate the benefits of such improvements on the basis of values of safety defined in such a way as to reflect the preferences and attitudes to safety of individual members of the public. However, given the technical complexity of many public sector safety decisions, it is also necessary to rely on expert analysis and informed judgement in reaching such decisions, so that preference-based values of safety should be regarded as being only one input to the decision-making process. In addition, the definition and estimation of the values themselves raise a number of practical and ethical questions. The purpose of this paper is to consider the role that preference-based values of safety can realistically be expected to play in these decision-making processes, given these difficulties and limitations.

Both theory on motivational crowding and recent empirical evidence suggest that nudging may sometimes backfire and actually crowd out prosocial behavior, due to decreased intrinsic motivation and warm glow. In this study, we tested this claim by investigating the effects of three types of nudges (default nudge, social norm nudge, and moral nudge) on donations to charity in a preregistered online experiment (N = 1098). Furthermore, we manipulated the transparency of the nudges across conditions by explicitly informing subjects of the nudges that were used. Our results show no indication that nudges crowd out prosocial behavior; instead, all three nudges increased donations. The positive effects of the nudges were driven by the subjects who did not perceive the nudges as attempts to manipulate their behavior, while donations among subjects who felt that the nudges were manipulative remained unaffected. Subjects’ self-reported happiness with their choice also remained unaffected. Thus, we find no indication that nudges crowded out warm glow when acting altruistically. Generally, our results are good news for the proponents of nudges in public policy, since they suggest that concerns about unintended motivational crowding effects on prosocial behavior have been overstated.

Boosts and nudges are two separate types of behavioral public policies, distinguished by the mechanisms through which they operate. We investigated whether this theoretical distinction translates into different effects when instances of these policy types are implemented in the context of energy consumption. In a long-term field randomized controlled trial, we competitively tested boosts against nudges. We found that boosts outperform nudges throughout a seven-month period in a student dormitory setting – both in terms of accumulated energy savings, as well as in keeping consumption consistently low during the experimental period. Furthermore, we explored the processes behind the boosts and nudges through a number of mechanistic markers and showed that the tested interventions indeed are instances of the respective types.

Behavioral economics research has helped with understanding charitable behavior and has shown that charities can encourage donations by carefully designing their pledges. However, there is still scope to extend current research on who gives, what drives the decision to donate and at what levels, especially when behavioral insights are applied in context. In cooperation with a major Italian charity for cancer research, this study implements a natural direct mail field experiment, with over 150,000 letters sent to donors. By exploring the behavioral responses to different donation anchors, evidence was found that, within the given framework, including donation menus significantly increased the average amount donated without affecting the likelihood of donation. Furthermore, introducing additional explanations of how to make a payment significantly increased overall returns. Lastly, individual heterogeneity (high- and low-frequency donors, as well as senior and junior donors) had a direct effect on donations.

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.

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.

The concept and use of choice architecture in public policy arouses warranted suspicion among scholars and the general public. Liberal scholars fear that without limitations, the contemporary wave of nudge theory and policies threaten individual autonomy. In this paper, I argue that the use of choice architecture in particular policy areas can not only enhance individual autonomy, but also work to mitigate larger social inequalities. Research demonstrates that too much choice leads to ‘choice paralysis’, especially in instances where knowledge is low and stakes are high. By limiting and nudging choices in these contexts, individuals are likely to feel less overwhelmed and more in control. A stronger sense of control and additional resources elevates the experience of autonomy felt by vulnerable populations (those with low knowledge and resources). This paper offers a theoretically robust defense of choice architecture by examining the relationship between choice architecture and autonomy.