We introduce a new method of varying the risk that bidders face in first-price private value auctions. We find that decreasing bidders' risk significantly reduces the degree of overbidding relative to the risk-neutral Bayesian-Nash equilibrium prediction. This implies that risk affects bidding...

We present results from a series of experiments that allow us to measure overbidding and, in particular, underbidding in first-price auctions. We investigate how the amount of underbidding depends on seemingly innocent parameters of the experimental setup. To structure our data we present and...

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...