Buyer's preferences over auctions depend on their measure of absolute risk aversion. If it is constant and they have independent private values, they are indifferent between a first-price auction (FPA), a second-price auction (SPA), and a first-price auction in which the number of bidders is...

This paper examines the use of stage mechanisms in implementation problems and provides a partial characterization of the set of subgam e perfect implementable choice rules. It is shown that, in many economic environments, virtually an y choice rule can be implemented. To illustrate the power of...

The authors extend E. Maskin's results on Nash implementation. First, they establish a condition that is both necessary and sufficient for Nash implementability if there are three or more agents (the case covered by Maskin's sufficiency result). Second--and more important--they examine the...

When drawing up a contract, it is often impracticable to specify all the relevant contingencies, and so contracts are typically incomplete. This paper considers the extent to which these gaps migh t be filled by building into the contract a mechanism for revising th e terms of trade. One...