We study ex post implementation in collective decision problems where monetary transfers cannot be used. We find that deterministic ex post implementation is impossible if the underlying environment is neither almost an environment with private values nor almost one with common values. Thus,...

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...

I investigate the design of effort-maximizing mechanisms when agents have both private information and convex effort costs, and the designer has a fixed prize budget. I first demonstrate that it is always optimal for the designer to utilize a contest with as many participants as possible....

Objects of different quality are to be allocated to agents. Agents can receive at most one object, and there are not enough high-quality objects for every agent. The value to the social planner from allocating objects to any given agent depends on that agent's private information. The social...

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 investigate equilibrium bidding in first-price auctions with asymmetric reserve prices. For example, the auctioneer may set a low reserve price for one subset of bidders and a high reserve price for others. When used to pursue a distributional objective, lowering the reserve price for some...

We analyze a setting common in privatizations, public tenders, and takeovers in which the ex post efficient allocation, i.e., the first best, is not implementable. Our first main result is that the open ascending auction is not second best because it is prone to rushes, i.e., all active bidders...

This paper considers the optimal degree of monetary-discretion when the central bank conducts policy based on its private information about the state of the economy and is unable to commit. Society seeks to maximize social welfare by imposing restrictions on the central bank's actions over time,...

This paper generalizes a conceptual insight in dynamic contracting with quasilinear payoffs: the principal does not need to pay any information rents for extracting the agent's 'new' private information obtained after signing the contract. This is shown in a general model in which the agent's...

For a partnership model with general type distributions and interdependent values, we derive the optimal dissolution mechanisms that, for arbitrary initial ownership, maximize any convex combination of revenue and social surplus. The solution involves ironing around typically interior worst-off...