We provide a complete answer regarding what social choice functions can be rationalizably implemented.

The theory of full implementation has been criticized for using integer/modulo games which admit no equilibrium (Jackson (1992)). To address the critique, we revisit the classical Nash implementation problem due to Maskin (1977, 1999) but allow for the use of lotteries and monetary transfers as...

For diþerent purposes, economists may use diþerent topologies on types. We characterize the relationship among these various topologies. First, we show that for any general types, convergence in the uniform-weak topology implies convergence in both the strategic topology and the uniform...

We study the robustness of interim correlated rationalizability to perturbations of higher-order beliefs. We introduce a new metric topology on the universal type space, called uniform weak topology, under which two types are close if they have similar first-order beliefs, attach similar...

This paper analyzes simultaneous ascending auctions of two different items, viewed as complements by multi-item bidders. The finding is that such auctions overly concentrate the goods to a multi-item bidder and never overly diffuse them to single-item bidders. The main reason is that some...

We study the design of profit maximizing single unit auctions under the assumption that the seller needs to incur costs to contact prospective bidders and inform them about the auction. With independent bidders’ types and possibly interdependent valuations, the seller’s problem can be...