Nicolas Jacquemet

Dishonest behaviours such as tax evasion impose significant societal costs. Ex ante honesty oaths—commitments to honesty before action—have been proposed as interventions to counteract dishonest behaviour, but the heterogeneity in findings across operationalizations calls their effectiveness into question. We tested 21 honesty oaths (including a baseline oath)—proposed, evaluated and selected by 44 expert researchers—and a no-oath condition in a megastudy involving 21,506 UK and US participants from Prolific.com who played an incentivized tax evasion game online. Of the 21 interventions, 10 significantly improved tax compliance by 4.5 to 8.5 percentage points, with the most successful nearly halving tax evasion. Limited evidence for moderators was found. Experts and laypeople failed to predict the most effective interventions, though experts’ predictions were more accurate. In conclusion, honesty oaths were effective in curbing dishonesty, but their effectiveness varied depending on content. These findings can help design impactful interventions to curb dishonesty.

Whether individuals feel confident about their own actions, choices, or statements being correct, and how these confidence levels differ between individuals are two key primitives for countless behavioral theories and phenomena. In cognitive tasks, individual confidence is typically measured as the average of reports about choice accuracy, but how reliable is the resulting characterization of within-and between-individual confidence remains surprisingly undocumented. Here, we perform a large-scale resampling exercise in the Confidence Database to investigate the reliability of individual confidence estimates, and of comparisons across individuals’ confidence levels. Our results show that confidence estimates are more stable than their choice-accuracy counterpart, reaching a reliability plateau after roughly 50 trials, regardless of a number of task design characteristics. While constituting a reliability upper-bound for task-based confidence measures, and thereby leaving open the question of the reliability of the construct itself, these results characterize the robustness of past and future task designs.

Under incomplete contracts, the mutual belief in reciprocity facilitates how traders create value through economic exchange. Creating such beliefs among strangers can be challenging even when they are allowed to communicate, because communication is cheap. In this paper, we first extend the literature showing that a truth-telling oath increases honesty to a sequential trust game with pre-play, fixed-form, and cheap-talk communication. Our results confirm that the oath creates more trust and cooperative behavior thanks to an improvement in communication; but we also show that the oath induces selection into communication -it makes people more wary of using communication, precisely because communication speaks louder under oath. We next designed additional treatments featuring mild and deterrent fines for deception to measure the monetary equivalent of the non-monetary incentives implemented by a truth-telling oath. We find that the oath is behaviorally equivalent to mild fines. The deterrent fine induces the highest level of cooperation. Altogether, these results confirm that allowing for interactions under oath within a trust game with communication creates significantly more economic value than the identical exchange institutions without the oath.

Du matin au soir, nous faisons toutes sortes de choix : conduire ou prendre le vélo, aller au supermarché ou à l’épicerie. Si ces décisions quotidiennes s’enchaînent souvent sans même qu’on en ait conscience, elles s’ajoutent à des décisions dont les enjeux sont autrement plus importants, qu’ils soient économiques, financiers, ou d’ordre environnemental, sociologique et culturel. Quels processus de décision se cachent derrière les réalités sociales qui déterminent le fonctionnement de l’économie ? Comment définir les coûts et les bénéfices entre lesquels nous devons arbitrer ? Pourquoi même l’absence de choix est-elle une forme de décision ? Comment les décisions individuelles se combinent-elles avec les décisions collectives ? Quelle est la palette d’outils permettant d’orienter les comportements ? L’économie comportementale apporte des réponses à ces questions en étudiant les décisions économiques à travers le prisme de facteurs rationnels, la comparaison des coûts et des bénéfices, mais aussi psychologiques, tels que les ressources cognitives, le contexte et le comportement des pairs.

Formal enforcement punishing defectors can sustain cooperation by changing incentives. In this paper we introduce a second effect of enforcement: it can also affect the capacity to learn about the group’s cooperativeness. Indeed, in contexts with strong enforcement, it is difficult to tell apart those who cooperate because of the threat of fines from those who are intrinsically cooperative types. Enforcement can then potentially have a negative dynamic impact on cooperation when it prevents learning. We provide theoretical and experimental evidence in support of this mechanism. Using a lab experiment with independent interactions and random rematching, we observe that, in early interactions, having faced an environment with fines in the past decreases current cooperation. We further show that this results from the interaction between enforcement and learning: the effect of having met cooperative partners has a stronger effect on current cooperation when this happened in an environment with no enforcement.

Economic homogamy is a well-documented fact in demography. The preferred interpretation of this phenomenon is a preference for “entre-soi,” but the characteristics of the spouses in a household condition not only their satisfaction in being together, but also their decisions on the division of labor. In this article, we present an approach that encompasses both the process of couple formation, the sharing of resources within the household, and the complementarity of spouses in couple activities. Studying German data from 2013 to 2019, we show that wage homogamy is concentrated at the top of the distribution, that education has a very important weight in spousal complementarities, and that wages and education play a similar role in household income-sharing arrangements.

Law and economics primarily focus on various legal rules’ capacity to rectify structural inefficiencies stemming from market failures, such as those related to preventive or criminal behaviors. Recent advancements in behavioral economics provide valuable insights into how economic agents respond to the rules they face, offering new perspectives for designing a range of legal rules and procedures. This article provides an overview of these developments as they apply to civil liability regimes, the design of criminal procedure, and criminal policy.