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...

We consider a general economy, where agents have private information about their types. Types can be multi-dimensional and potentially interdependent. We show that, if the interim distribution of types is common knowledge (the exact number of agents for each type is known), then a mechanism...

Governments must usually take policy decisions with an imperfect knowledge of the economic actors' type or the actors' effort level. These issues are addressed within the framework of classic adverse selection or moral hazard models. I discuss in this paper how would the government’s and the...

This paper considers a multi-period setting where a monopolist, with short-term commitment, rents one unit of a durable good to a single consumer in every period. The consumer's valuation constitutes his private information and remains constant over time. By using a mechanism design approach,...

This paper provides a complete characterization of equilibria in a game-theoretic version of Rothschild and Stiglitz's (1976) model of competitive insurance. I allow for stochastic contract offers by insurance firms and show that a unique symmetric equilibrium always exists. Exact conditions...

We study a principal-agent model with moral hazard and adverse selection. Risk-neutral agents with limited liability have arbitrary private information about the distribution of outputs and the cost of effort. We show that under a multiplicative separability condition, the optimal mechanism...