This paper provides evidence that free riders are heavily punished even if punishment is costly and does not provide any material benefits for the punisher. The more free riders negatively deviate from the group standard the more they are punished. As a consequence, the existence of an...

This paper shows that reciprocity has powerful implications for many economic domains. It is an important determinant in the enforcement of contracts and social norms and enhances the possibilities of collective action greatly. Reciprocity may render the provision of explicit incentive...

In this paper we provide experimental evidence indicating that incentive contracts may cause a strong crowding out of reciprocity-driven voluntary cooperation. This crowding out effect constitutes costs of incentive provision that have been largely neglected by economists. In our experiments the...

We study behavior within a simple principal--agent experiment. Our design allows for a large class of linear contracts. Principals can offer any feasible combination of (negative) fixed wages and incentives in the form of return sharing. This great contractual flexibility allows us to study...

We investigate to what extent contribution decisions to a public good depend on the contributions of others. We employ a novel experimental technique that allows us to elicit people's willingness to be conditionally cooperative, i.e., to contribute more to the public good the more the other...

This paper presents an experimental examination of the Falkinger (1996) mechanism or overcoming the free-rider problem. The basic idea of the mechanism is that deviations from the mean contribution to the public good are taxed and subsidized. The mechanism has attractive properties because (i)...

Recent evidence highlights the importance of social norms in many economic relations. However, many of these relationships are long-term and provide repeated game incentives for performance. We experimentally investigate interaction effects of reciprocity and repeated game incentives in two...