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 by the intention underlying this action. The theory...

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...

Problems which can only be resolved through international cooperation are increasing. Due to this increase, states cooperate more than ever with each other and with international organizations (IOs) but often insufficiently to solve the problems. When social scientists analyze the potential for...