Following merger, an optimal mechanism discriminates against merging bidders with higher reserve prices and by allocating more often towards non-merging bidders. In this setting, we show that mergers always harm the auctioneer, benefit non-merging bidders, can increase total surplus, and have...

In this paper, we derive estimators of, and closed-form (non-integral) expressions for, the distribution of bids in an extreme value, asymmetric, second-price, private-values auction. In equilibrium, prices (winning bids) and shares (winning probabilities) have a simple monotonic...

In a private values, open auction, we show that bidder surplus can be expressed as a simple difference between unconditional moments of order statistics. The strength of the result is its simplicity and generality, as we dispense with the typical assumptions of independence and/or symmetry. We...

We examine theoretically and experimentally two countervailing effects of industry concentration in common value auctions. Greater concentration of information among fewer bidders reduces competition but increases the precision of private estimates. We demonstrate that this generally leads to...