This paper shows that the possibility of collusion between an agent and a supervisor imposes no restrictions on the set of implementable social choice functions (SCF) and associated payoff vectors. Any SCF and any payoff profile that are implementable if the supervisor's information was public...

In Buy-It-Now auctions, sellers can post a take-it-or-leave-it price offer prior to an auction. While the literature almost exclusively looks at buyers in such combined mechanisms, the current paper summarizes results from the sellers' point of view. Buy-It-Now auctions are complex mechanisms...

We study the optimal entry fee in a symmetric private value first-price auction with signaling, in which the participation decisions and the auction outcome are used by an outside observer to infer the bidders’ types. We show that this auction has a unique fully separating equilibrium bidding...

We study optimal auctions in a symmetric private values setting, where bidders' care about winning the object and a receiver's inference about their type. We reestablish revenue equivalence when bidders' signaling concerns are linear, and the auction makes participation observable via an entry...

We consider a multi-dimensional procurement problem in which sellers have private information about their costs and about a possible design flaw. The information about the design flaw is necessarily correlated. We solve for the optimal Bayesian procurement mechanism that implements the efficient...

We study optimal mechanisms for a utilitarian designer who seeks to assign a finite number of goods to a group of ex ante heterogeneous agents with unit demand. The agents have heterogeneous marginal utilities of money, which may naturally arise in environments where agents have different wealth...