We explore in an experiment what leads to the breakdown of partnerships. Subjects are assigned a partner and participate in a repeated public good game with stochastic outcomes. They can choose each period between staying in the public project or working on their own. There is excessive exit as...

Unlike previous attempts to implement cooperation in a prisoners' dilemma game with an infinite horizon in the laboratory, we focus on extended prisoners' dilemma games in which a second (pure strategy) equilibrium allows for voluntary cooperation in all but the last round. Our four main...

This paper provides a new way to identify conditional cooperation in a real-time version of the standard voluntary contribution mechanism. Our approach avoids most drawbacks of the traditional procedures because it relies on endogenous cycle lengths, which are defined by the number of...

Costly signaling of commitment to a group has been proposed as an explanation for participation in religion and ritual. But if the signal’s cost is too small, freeriders will send the signal and behave selfishly later. Effective signaling may then be prohibitively costly. If the average level...

Norms play an important role in establishing social order. The current literature focuses on the emergence, maintenance and impact of norms with regard to coordination and cooperation. However, the issue of norm-related conflict deserves more attention. We develop a general theory of "normative...

In experiments, people behave more cooperatively when they are aware of an external threat, while in the field, we observe surprisingly high levels of cooperation and altruism within groups in conflict situations such as civil wars. We provide an explanation for these phenomena. We introduce a...

Often in cooperative situations, many aspects of the decision-making environment are uncertain. We investigate how cooperation is shaped by the way information about risk is presented (from description or from experience) and by differences in risky environments. Drawing on research from risky...

We study conditional cooperation based on a sequential two-person linear public good game in which a trusting first contributor can be exploited by a second contributor. After playing this game the first contributor is allowed to punish the second contributor. The consequences of sanctioning...

We report on an experiment designed to explore whether and how anger affects future levels of cooperation. Participants play three consecutive one-shot games. In between two identical two-person public goods games there is a mini dictator game that, depending on the treatment, either gives or...

Extensive research on human cooperation in social dilemmas has shown that individuals condition their behaviour upon the behaviour of others. However, few attempts have been made to disentangle the motivations backing conditional cooperation. We try to assess the relative importance of three...