This paper evaluates the state of contact hypothesis research from a policy perspective. Building on Pettigrew and Tropp's (2006) influential meta-analysis, we assemble all intergroup contact studies that feature random assignment and delayed outcome measures, of which there are 27 in total, nearly two-thirds of which were published following the original review. We find the evidence from this updated dataset to be consistent with Pettigrew and Tropp's (2006) conclusion that contact “typically reduces prejudice.” At the same time, our meta-analysis suggests that contact's effects vary, with interventions directed at ethnic or racial prejudice generating substantially weaker effects. Moreover, our inventory of relevant studies reveals important gaps, most notably the absence of studies addressing adults' racial or ethnic prejudices, an important limitation for both theory and policy. We also call attention to the lack of research that systematically investigates the scope conditions suggested by Allport (1954) under which contact is most influential. We conclude that these gaps in contact research must be addressed empirically before this hypothesis can reliably guide policy.

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).

Neuroimaging methods provide insight into the neural mechanisms underlying the decision process, characterizing choice at the individual level and, in a growing number of contexts, predicting national- and market-level behavior. This dual capacity to examine heterogeneity while forecasting aggregate choice is particularly beneficial to those studying environmental decision-making. To effectively reduce residential energy usage and foster other pro-environmental behaviors, policy-makers must understand the effects of information frames and behavioral nudges across individuals who hold a diverse array of attitudes toward the environment and face a broad range of barriers to action. This paper articulates the potential of neuroeconomic methods to aid environmental policy-makers interested in behavior change, especially those interested in closing the energy efficiency gap. Investigation into the roles of affect, eco-labeling and social norms will be discussed, as well as personal identity and climate change beliefs. Combining neuroimaging with behavioral economics experiments can inform the development of effective messaging, characterize the influence of individual differences on the decision process and aid in forecasting the efficacy of policy interventions at scale.

When people make decisions with a pre-selected choice option – a ‘default’ – they are more likely to select that option. Because defaults are easy to implement, they constitute one of the most widely employed tools in the choice architecture toolbox. However, to decide when defaults should be used instead of other choice architecture tools, policy-makers must know how effective defaults are and when and why their effectiveness varies. To answer these questions, we conduct a literature search and meta-analysis of the 58 default studies (pooled n = 73,675) that fit our criteria. While our analysis reveals a considerable influence of defaults (d = 0.68, 95% confidence interval = 0.53–0.83), we also discover substantial variation: the majority of default studies find positive effects, but several do not find a significant effect, and two even demonstrate negative effects. To explain this variability, we draw on existing theoretical frameworks to examine the drivers of disparity in effectiveness. Our analysis reveals two factors that partially account for the variability in defaults’ effectiveness. First, we find that defaults in consumer domains are more effective and in environmental domains are less effective. Second, we find that defaults are more effective when they operate through endorsement (defaults that are seen as conveying what the choice architect thinks the decision-maker should do) or endowment (defaults that are seen as reflecting the status quo). We end with a discussion of possible directions for a future research program on defaults, including potential additional moderators, and implications for policy-makers interested in the implementation and evaluation of defaults.

Many public policies are designed to counteract commonly made decisions that result in poor health. These policies have primarily been informed by the behavioural economics of decision making. Underappreciated in this conversation has been the perspective from neuroscience, despite its recent success – and the likelihood of future progress – in advancing our understanding of the neural basis for health-related decisions. Using tobacco control as an example, we provide a concise overview of how public health policies can and should be informed by neuroscience. We propose that such input can improve policies by increasing their effectiveness, improving screening efficiency and informing relevant ethical considerations. Finally, we recognise limitations and highlight roles that key stakeholders can play in incorporating neuroscientific evidence for the benefit of public policy.

From an ethical standpoint, transparency is an essential requirement in public policy-making. Ideally, policy-makers are transparent and actively disclose the presence, purpose and means of a decision aid. From a practical point of view, however, transparency has been discussed as reducing the effectiveness of decision aids. In the present paper, we elaborate on how transparency affects the effectiveness of defaults. In three experiments, we manipulated whether the endorser was transparent about the default or not and assessed participants’ decisions to opt out or comply. Throughout the experiments, we found that proactive transparency reduced opt-out rates as compared to a non-transparent default condition. Moreover, proactive disclosure of a default reduced opt-out rates as compared to informed control groups, where participants imagined they had retrieved the default-related information by themselves (Studies 1 and 2). The results further indicate that a lack of proactive disclosure may lead targets to perceive the endorser as less sincere and to feel deceived, which in turn hinders the effectiveness of the default. In general, our findings lend support to the proactive transparency paradigm in governance and show that a default-based policy can be transparent and effective at the same time.

Disclosure mandates are pervasive. Though designed to inform consumers, such mandates may lead consumers to draw false inferences – for example, that a product is harmful when it is not. When deciding to require disclosure of an ingredient in or characteristic of a product, regulators may be motivated by evidence that the ingredient or characteristic is harmful to consumers. But they may also be motivated by a belief that consumers have a right to know what they are buying or by interest-group pressure. Consumers who misperceive the regulator's true motive, or mix of motives, will draw false inferences from the mandated disclosure. If consumers think that the disclosure is motivated by evidence of harm, when in fact it is motivated by a belief in a right to know or by interest-group pressure, then they will be inefficiently deterred from purchasing the product. We analyze this general concern about disclosure mandates. We also offer survey evidence demonstrating that the risk of false inferences is serious and real.

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.

Persuading people to choose strong passwords is challenging. One way to influence password strength, as and when people are making the choice, is to tweak the choice architecture to encourage stronger choice. A variety of choice architecture manipulations (i.e. ‘nudges’) have been trialled by researchers with a view to strengthening the overall password profile. None has made much of a difference so far. Here, we report on our design of an influential behavioural intervention tailored to the password choice context: a hybrid nudge that significantly prompted stronger passwords. We carried out three longitudinal studies to analyse the efficacy of a range of ‘nudges’ by manipulating the password choice architecture of an actual university web application. The first and second studies tested the efficacy of several simple visual framing ‘nudges’. Password strength did not budge. The third study tested expiration dates directly linked to password strength. This manipulation delivered a positive result: significantly longer and stronger passwords. Our main conclusion was that the final successful nudge provided participants with absolute certainty as to the benefit of a stronger password and that it was this certainty that made the difference.

There have been few empirical studies on how consumers respond to their loss experience over time when choosing between high- and low-deductible health insurance plans. To address this question, we designed a ten-period web-based experiment to explore how subjects respond to the presence or absence of illness-related costs in a given period when making their future health insurance choices when they are explicitly informed that future premiums or loss probabilities will not change over time. A sizable minority of the respondents who initially chose high-deductible plans switched after a loss, and switching is more likely if they self-report negative emotional responses to experiencing an uninsured loss. Switching from low- to high-deductible plans is less likely and less responsive to loss experience. The study reveals that many individuals make their health insurance choices by considering factors not included in classical economic models of choice.

People's risk estimates often do not align with the evidence available to them. In particular, people tend to discount bad news (such as evidence suggesting their risk of being involved in a car accident is higher than they thought) as compared to good news (evidence suggesting it is lower) – this is known as the belief update bias. It has been assumed that individuals use motivated reasoning to rationalise away unwanted evidence (e.g., “I am a safe driver, thus these statistics do not apply to me”). However, whether reasoning is required to discount bad news has not been tested directly. Here, we restrict cognitive resources using a cognitive load (Experiment 1) and a time restriction manipulation (Experiment 3) and find that while these manipulations diminish learning in general, they do not diminish the bias. Furthermore, we also show that the relative neglect of bad news happens the moment new evidence is presented, not when participants are subsequently prompted to state their belief (Experiment 2). Our findings suggest that reasoning is not required for bad news to be discounted as compared to good news.

Received research shows numerous motives for migration, but fewer reasons for return migration. This paper aims to correct this imbalance. Twelve reasons for return migration are presented and discussed briefly. The reasons listed are derived from research on migration conducted by the author in the course of the past three and a half decades. The purpose of the paper is to pull together insights gained from that research so as to formulate a base for future inquiry, both analytical and empirical. In addition, just as research on motives for migration can help to establish the reasons for return migration, research on the latter can help to deepen understanding of the former. Moreover, in a great many circumstances and for a variety of reasons, countries that host migrants may want them to leave. In such circumstances, enacting policies that align with motives for return migration will be more efficient than devising measures that are independent of these motives.