We report data on the experimental articles published from 2000 to 2021 in seven leading general-interest economics journals. We also look at time trends in the characteristics of the published experimental articles, including citations and the nationality of the authors. We find an overall increasing trend in the publication of non-lab experiments in all journals. By contrast, the share of lab experiments has more than halved in the AER and remained low in other Top five journals. The diverging trends for non-lab and lab experiments are not universal as the shares of both have increased in two other high-ranking economics journals (JEEA and EJ). We also observe some heterogeneities in publication, citations, rankings, and locations of authors' affiliations across journals and types of experiments.

Recruitment of representative and generalizable adult samples is a major challenge for researchers conducting economic field experiments. Limited access to representative samples or the high cost of obtaining them often leads to the recruitment of non-representative convenience samples. This research compares the findings from two field experiments involving 860 adults: one from a non-representative in-person convenience sample and one from a representative online counterpart. We find no meaningful differences in the key behaviors of interest between the two samples. These findings contribute to a growing body of literature demonstrating that non-representative convenience samples can be sufficient in certain contexts.

Indoor air pollution is one of the leading causes of morbidity and mortality worldwide, but its sources and impacts are largely misunderstood by the public. In a randomised controlled trial including 281 households in France, we test two interventions aimed at changing indoor polluting behaviour by raising households’ awareness of health risks associated with indoor air pollution. While both generic and personalised information increased knowledge, only personalised information including social comparison feedback changed behaviour, leading to a reduction of indoor PM2.5 (particulate matter with an aerodynamic diameter ≤2.5 µm) emissions by 20% on average. Heterogeneous treatment effects show that this effect is concentrated on the most polluted households at baseline, for whom the reduction reaches 40%.

Many efforts to persuade others politically employ interpersonal conversations. A recurring question is whether the participants in such conversations are more readily persuaded by others who share their demographic characteristics. Echoing concerns that individuals have difficulties communicating across differences, research finds that individuals perceive demographically similar people as more trustworthy, suggesting shared demographics could facilitate persuasion. In a survey of practitioners and scholars, we find many share these expectations. However, dual-process theories suggest that messenger attributes are typically peripheral cues that should not influence persuasion when individuals are effortfully thinking, such as during interpersonal conversations. Supporting this view, we analyze data from eight experiments on interpersonal conversations across four topics (total N = 6, 139) and find that shared demographics (age, gender, or race) do not meaningfully increase their effects. These results are encouraging for the scalability of conversation interventions, and suggest voters can persuade each other across differences.

We study how an intervention combining youth intergroup contact and sports affects intergroup relations in the context of an active conflict. We first conduct a randomized controlled trial (RCT) of one-year program exposure in Israel. To track effects of a multiyear exposure, we then use machine-learning techniques to fuse the RCT with the observational data gathered on multiyear participants. This analytical approach can help overcome frequent limitations of RCTs, such as modest sample sizes and short observation periods. Our evidence cannot affirm a one-year effect on outgroup regard and ingroup regulation, although we estimate benefits of multiyear exposure among Jewish-Israeli youth, particularly boys. We discuss implications for interventions in contexts of active conflict and group status asymmetry.

Politicians are exposed to a constant flow of information about societal problems. However, they have limited resources and need to prioritize. So, which information should they pay attention to? Previous research identifies four types of information that may matter: public concern about a problem, problem attention by rival parties, news stories about problems, and statistical problem indicators. We are the first to contrast the four types of information through a field experiment with more than 6,000 candidates and multiple elite interviews in Denmark. The candidates received an email invitation to access a specially tailored report that randomly highlighted one of the four types of information. Statistical indicators and public opinion were accessed the most (26.9 per cent and 26.5 per cent of candidates in the two conditions). Our results provide new and important evidence about the types of information politicians consider when addressing societal problems.

While experiments on elections represent a popular tool in social science, the possibility that experimental interventions could affect who wins office remains a central ethical concern. I formally characterize electoral experimental designs to derive an upper bound on aggregate electoral impact under different assumptions about interference. I then introduce a decision rule based on comparison of this bound to predicted election outcomes to determine whether an experiment should be implemented. Researchers can mitigate the possibility of affecting aggregate outcomes by reducing the saturation of treatment or focusing experiments in districts and electoral systems where treated voters are less likely to be pivotal. These conditions identify novel trade-offs between adhering to ethical commitments and the statistical power and external validity of electoral experiments. More broadly, this paper shows that the formalization of an ethical objective facilitates a closer mapping between ethical considerations and experimental design than is currently practiced.

This study adds to the analogic perspective-taking literature by examining whether an online perspective-taking intervention affects both antisemitic attitudes and behaviors – in particular, engagement with antisemitic websites. Subjects who were randomly assigned to the treatment viewed a 90-s video of a college student describing an experience with antisemitism and reflected on its similarity to their own experiences. In a survey, treated subjects reported greater feelings of sympathy (+29 p.p.), more positive feelings toward Jews, a greater sense that Jews are discriminated against, and more support for policy solutions (+2–4 p.p.). However, these effects did not persist after 14 days. Examining our subjects’ web browsing data, we find a 5% reduction in time spent viewing antisemitic content during the posttreatment period and some limited, suggestive evidence of effects on the number of site visits. These findings provide the first evidence that perspective-taking interventions may affect online browsing behavior.

Measuring risk preferences using monetary incentives is costly. In the field, it might be also unfair and unsafe. The commonly used measure of Holt and Laury (2002) relies on a dozen lottery choices and payments, which make it time consuming and expensive. It also raises moral concerns as a result of the unequal payments generated by good and bad luck. Paying some but not all subjects may also create tensions between the researcher and subjects. In a pre-registered study in Honduras, Nigeria and Spain, we use a short version of Holt and Laury where we address all three concerns. We find in the field that not paying at all or paying with and without probabilistic rules makes no difference. Our hypothetical and short version makes our measurement of risk cheaper, fairer and safer.

Political elites increasingly express interest in evidence-based policymaking, but transparent research collaborations necessary to generate relevant evidence pose political risks, including the discovery of sub-par performance and misconduct. If aversion to collaboration is non-random, collaborations may produce evidence that fails to generalize. We assess selection into research collaborations in the critical policy arena of policing by sending requests to discuss research partnerships to roughly 3,000 law enforcement agencies in 48 states. A host of agency and jurisdiction attributes fail to predict affirmative responses to generic requests, alleviating concerns over generalizability. However, across two experiments, mentions of agency performance in our correspondence depressed affirmative responses – even among top-performing agencies – by roughly eight percentage points. Many agencies that initially indicate interest in transparent, evidence-based policymaking recoil once performance evaluations are made salient. We discuss several possible mechanisms for these dynamics, which can inhibit valuable policy experimentation in many communities.

The share of basic services that NGOs deliver has grown dramatically in developing countries due to increased receipt of aid and philanthropy in these countries. Many scholars and practitioners worry that NGOs reduce reliance on government services and, in turn, lower demand for government provision and undermine political engagement. Others argue that NGOs prop-up poorly performing governments that receive undeserved credit for the production, allocation, or welfare effects of NGO services. Using original surveys and a randomized health intervention, implemented in parallel to a similar universal government program, this article investigates the long-term effect of NGO provision on political attitudes and behavior. Access to NGO services increased preferences for NGO, relative to government, provision. However, political engagement and perceptions of government legitimacy were unaffected. Instead, the intervention generated political credit for the incumbent president. This study finds that citizens see NGOs as a resource that powerful government actors control, and they reward actors who they see as responsible for allocation of those resources.

Field experiments which test the application of behavioural insights to policy design have become popular to inform policy decisions. This study is the first to empirically examine who and what drives these experiments with public partners. Through a mixed-methods approach, based on a novel dataset of insights from academic researchers, behavioural insight team members and public servants, I derive three main results: First, public bodies have a considerable influence on study set-up and sample design. Second, high scientific standards are regularly not met in cooperative field experiments, mainly due to risk aversion in the public body. Third, transparency and quality control in collaborative research are low with respect to pre-analysis plans, the publication of results and medium or long-term effects. To remedy the current weaknesses, the study sketches out several promising ways forward, such as setting up a matchmaking platform for researchers and public bodies to facilitate cooperation, and using time-embargoed pre-analysis plans.

A substantial body of research has found biased recruitment in a variety of societal spheres. We study selection in the judiciary, a domain that has received less attention than the economic and political spheres. Our field experiment took place in the midst of a Swedish government campaign encouraging ordinary citizens to contact local parties, which are responsible for recruiting lay judges (jurors) and put themselves forward as lay judge candidates. Parties’ responsiveness to citizen requests does not seem to favor their own sympathizers, does not vary at all with signals of gender, and is only marginally affected by ethnicity and age. Given the potential importance of ideology and identity in judicial decision-making, the finding that there is little bias with respect to these factors at this first stage of the recruitment process is reassuring from the perspective of impartiality.

To what extent can civil rights NGOs protect ethnic minorities against unequal treatment? We study this question by combining an audit experiment of 1260 local governments in Hungary with an intervention conducted in collaboration with a major Hungarian civil rights NGO. In the audit experiment we demonstrated that Roma individuals were about 13 percent-points less likely to receive responses to information requests from local governments, and the responses they received were of substantially lower quality. The intervention that reminded a random subset of local governments of their legal responsibility of equal treatment led to a short-term reduction in their discriminatory behavior, but the effects of the intervention dissipated within a month. These findings suggest that civil rights NGOs might face substantive difficulties in trying to reduce discrimination through simple information campaigns.

We fielded an experiment on a sample of approximately 400 Black state legislators to test whether they would be more responsive to an email that mentioned the National Association for the Advancement of Colored People (NAACP) relative to an email that mentioned Black Lives Matter (BLM). The experiment tested Cohen's theory of secondary marginalization (1999), whereby relatively advantaged members of a marginalized group regulate the behavior, attitudes, and access to resources of less advantaged members of the group. We expected that Black legislators would be less responsive to an email that referenced BLM, an organization that is associated with more marginalized members of the Black community. Contrary to our hypothesis, Black legislators were as responsive to emails referencing inspiration from BLM as they were to emails referencing inspiration from the NAACP. Thus, we do not find any evidence of intragroup discrimination by Black state legislators. To our knowledge, this is the first field experiment to test Cohen's theory of secondary marginalization.1