In-group favoritism in social dilemma situations is one of the main findings of studies in Social Identity Theory. We investigate what causes the in-group bias: is it due to mere group affiliation or, alternatively, is guilt-aversion a possible explanation? We induce group membership in a...

We analyse pricing, effort and tipping decisions in the online service "Google Answers". While users set a price for the answer to their question ex ante, they can additionally give a tip to the researcher ex post. In line with the related experimental literature we find evidence that tipping is...

Recent research has cast some doubt on the general validity of outcome-based models of social preferences. We develop a model based on cognitive dissonance that focuses on the importance of self-image. An experiment (a dictator game variant) tests the model. First, we find that subjects whose...

We investigate to what extent genuine social preferences can explain observed other-regarding behavior. In a dictator game variant subjects can choose whether to learn about the consequences of their choice for the receiver. We find that a majority of subjects showing other-regarding behavior...