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...

In this paper we study equilibrium- and experimental bidding behaviour in first-price and second price auctions with outside options. We find that bidders do respond to outside options and to variations of common knowledge about competitors' outside options. However, overbidding in first-price...

Deviations from equilibrium bids in auctions can be related to inconsistent expectations with correct best replies (see Eyster and Rabin, 2005; Crawford and Iriberri, 2007) or correct expectations but small (perhaps quantal-response) mistakes in best replies (see Goeree et al., 2002). To distinguish...

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...