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...

Internationally, there is no consensus concerning the legal and moral judgment of prostitution. Nevertheless, there is an overwhelming agreement on the need to fight sexual slavery. We analyze how a law - introduced to punish clients of commercial sex services - affects market outcomes. More...

This note analyses investment and risk-taking in a simple agency model of public regulation/procurement borrowed from Laffont & Tirole (1993). We show that the principal will overinvest or underinvest depending on whether investment is marginally more productive in bad or in good states. Due to...

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...

I study the properties of optimal long-term contracts in an environment in which the agent.s type evolves stochastically over time. The model stylizes a buyer-seller relationship but the results apply quite naturally to many contractual situations including regulation and optimal...

We develop a theory of price discrimination in many-to-many matching markets in which agents' preferences are vertically and horizontally differentiated. The optimal plans induce negative assortative matching at the margin: agents with a low value for interacting with other agents are included...

We study centralized many-to-many matching in markets where agents have private information about (vertical) characteristics that determine match values. Our analysis reveals how matching patterns reflect cross-subsidization between sides. Agents are endogenously partitioned into consumers and...

In markets with quality unobservable to buyers, third-party certification is often the only instrument to increase transparency. While both sellers and buyers have a demand for certification, its role differs fundamentally: sellers use it for signaling, buyers use it for inspection. Seller...

We examine the design of incentive-compatible screening mechanisms for dynamic environments in which the agents' types follow a (possibly non-Markov) stochastic process, decisions may be made over time and may affect the type process, and payoffs need not be time-separable. We derive a formula...

How does renegotiation affect contracts between a principal and an agent subject to persistent private information and moral hazard? This paper introduces a concept of renegotiationproofness, which adapts to stochastic games the concepts of weak renegotiation-proofness and internal consistency...