Louis-André Gérard-Varet

Balanced Bayesian mechanisms

We present a new condition on beliefs that guarantee the Bayesian implementability of all efficient social decision rules. We show that this condition is easy to verify and is both more interpretable and more general than the conditions that are found in the literature. We also study conditions guaranteeing the Bayesian implementability of all social decision rules with balanced budget mechanisms.

On pricing the priceless: Comments on the economics of the visual art market

Abstract Behaviour in the arts is often related to pleasure and imagination. However, art objects (paintings, pieces of sculpture and others) have been traded on markets for a long time. More importantly, the place attributed to an artist by contemporary aesthetic judgement more or less depends upon markets. We consider here different questions about art objects as commodities, markets and prices, the returns to art, including comments on the comparison of prices of paintings and stock-market fluctuations.

Correlation, independence, and Bayesian incentives

Our goal is to describe the state of the art on Bayesian mechanisms when utility is transferable and only balanced transfers are admissible. New results will be proved along the way, but they will be integrated to the overall picture. We first study a condition on the information structure of the agents (condition B) which is necessary and sufficient to guarantee implementation of any decision rule. We prove constructively that condition B holds generically. We further analyze another condition (condition C), sufficient to guarantee implementation of any efficient decision rule and provide a simple interpretation. Also, we build a counterexample showing that condition C is not necessary to guarantee implementation of any efficient decision rule and then provide a necessary and sufficient condition. A counterexample is constructed to show that there does not always exist efficient Bayesian mechanisms, with three agents. Finally, we exhibit conditions on the information structures that guarantee unique implementation, and show that they hold generically.

Non-Transferable Utility and Bayesian Incentives

Whenever information is decentralized, efficient collective decisions have to rely on the pieces of information that each individual privately controls. Incentives have to be provided to guarantee proper revelation of these private informations. The literature on mechanism design under incomplete information addresses the question.1