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...

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...