Field evidence suggests that agents belonging to the same group tend to behave similarly, i.e., behavior exhibits social interaction effects. Testing for such effects raises severe identification problems. We conduct an experiment that avoids these problems. The main design feature is that each...

We provide a test of the role of social preferences and beliefs in voluntary cooperation and its decline. We elicit individuals' cooperation preferences in one experiment and use them as well as subjects' elicited beliefs to explain contributions to a public good played repeatedly. We find...

We report an experiment comparing sequential and simultaneous contributions to a public good in a quasi-linear two-person setting (Varian, Journal of Public Economics, 1994). Our findings support the theoretical argument that sequential contributions result in lower overall provision than...

Does the cultural background influence the success with which genetically unrelated individuals cooperate in social dilemma situations? In this paper we provide an answer by analyzing the data of Herrmann et al. (Science 2008, pp. 1362-1367), who study cooperation and punishment in sixteen...

We introduce “group cohesion” to study the economic relevance of social relationships in team production. We operationalize measurement of group cohesion, adapting the “oneness scale” from psychology. A series of experiments, including a pre-registered replication, reveals strong...

We experimentally examine how the incentive to defect in a social dilemma affects conditional cooperation. In our first study we conduct online experiments in which subjects play eight Sequential Prisoner’s Dilemma games with payoffs systematically varied across games. We find that few second...

We study how an individual's compliance with social norms is influenced by other actors' norm compliance. In a repeated non-strategic Take-or-Give donation experiment we show that giving is considered socially appropriate while taking is socially inappropriate. Observing norm violations erodes...

The prisoner’s dilemma (PD) is arguably the most important model of social dilemmas, but our knowledge about how a PD’s material payoff structure affects cooperation is incomplete. In this paper we investigate the effect of variation in material payoffs on cooperation, focussing on one-shot...