Most economic models are based on the self-interest hypothesis that assumes that all people are exclusively motivated by their material self-interest. In recent years experimental economists have gathered overwhelming evidence that systematically refutes the self-interest hypothesis and suggests...

In recent years a large number of experimental studies have documented the existence of strong reciprocity among humans. Strong reciprocity means that people willingly repay gifts and punish the violation of cooperation and fairness norms even in anonymous one-shot encounters with genetically...

We study how the distribution of other-regarding preferences develops with age. Based on a set of allocation choices, we can classify each of 717 subjects, aged 8 to 17 years, as either egalitarian, altruistic, or spiteful. Varying the allocation recipient as either an in-group or an out-group...

Increasing inequality and associated egalitarian sentiments have again put redistribution on the political agenda. Other-regarding preferences may also affect support for redistribution, but knowledge about their distribution in the broader population and how they are associated with political...

The empirical evidence on the existence of social preferences—or lack thereof—is predominantly based on student samples. Yet, knowledge about whether these findings can be extended to the general population is still scarce. In this paper, we compare the distribution of social preferences in...

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...

We show experimentally that fairness concerns may have a decisive impact on both the actual and the optimal choice of contracts in a moral hazard context. Explicit incentive contracts that are optimal according to self-interest theory become inferior when some agents value fairness. Conversely,...