In this paper we use an experiment to compare a theory of risk aversion and a theory of spite as an explanation for overbidding in auctions. As a workhorse we use the second-price all-pay and the first-price winner-pay auction. Both risk and spite can be used to rationalize deviations from risk...

We study how punishment influences conditional cooperation. We ask two questions: 1) how does conditional cooperation change if a subject can be punished and 2) how does conditional cooperation change if a subject has the power to punish others. In particular, we disentangle the decision to be a...