We introduce contingent auction mechanisms, which is a superset of combinatorial auctions, and where bidders submit bids on packages that are contingent on the whole final assignment. Without externalities, the Vickrey and the Ausubel-Milgrom Proxy Auction are both robust if items are perceived...

From a theory viewpoint, the use of auctions with zero public reserve prices also called absolute auctions, or the use of auctions with secret reserve prices is somehow puzzling despite being common. By allowing that buyers differ in their processing of past data regarding how the participation...

With exogenous participation, strong bidders should be discriminated against weak bidders to maximize revenues (Myerson 1981). When participation is endogenous and the set of potential entrants is large, optimal discrimination if any takes a very different form. Without incumbents, there should...

When bidders are not substitutes, we show that there is no standard ascend-ing auction that implements a bidder-optimal competitive equilibrium under truthful bidding. Such an impossibility holds also in environments where the Vickrey payoff vector is a competitive equilibrium payoff and is thus...

In the symmetric independent private value model, we revisit auctions with entry by adding two additional ingredients: difficulties to commit to the announced mechanism, in particular not to update the reserve price after bidders took their entry decisions, and seller's ex ante uncertainty on...

Brendstrup (2007) and Brendstrup and Paarsch (2006) claim that sequential English auction models with multi-unit demand can be identified from the distribution of the last stage winning price and without any assumption on bidding behavior in the earliest stages. We show that their identification...