This study reports data from a field experiment that was conducted to investigate the relevance of gift-exchange for charitable giving. Roughly 10,000 solicitation letters were sent to potential donors in the experiment. One third of the letters contained no gift, one third contained a small...

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...

This paper presents a formal theory of reciprocity. Reciprocity means that people reward kind actions and punish unkind ones. The theory takes into account that people evaluate the kindness of an action not only by its consequences but also the intention underlying this action. The theory...

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...

During the last two decades economists have made much progress in understanding incentives, contracts and organisations. Yet, they constrained their attention to a very narrow and empirically questionable view of human motivation. The purpose of this paper is to show that this narrow view of...

In this paper we show that a simple model of fairness preferences explains major experimental regularities of common pool resource (CPR) experiments. The evidence indicates that in standard CPR games without communication and without sanctioning possibilities inefficient excess appropriation is...