Claude d'Aspremont-Lynden

Market power, coordination failures and endogenous fluctuations

vVe analyse an overlapping generations economy with Cournotian monopolistic competition in the produced goods markets and perfect competition in the labour market. All prices are perfectly flexible and no adjustments costs are introduced. We show that these features lead to properties qualitatively different from those obtained when all markets are perfectly competitive. First there is a possibility of multiple Pareto-ranked temporary or stationary equilibria. Second, a preliminary analysis of the intertemporal equilibria shows that imperfect competition opens up new possibilities of endogenous fluctuations, and may lead to non-monotonicity of all equilibria in prices and output. These results are essentially based on two features, naturally associated with imperfect competition, increasing returns to scale and the variability of oligopolistic market power as a consequence of the variability of demand elasticity.

A Welfarist Version of Harsanyi's Aggregation Theorem

Harsanyi’s Aggregation Theorem has often been dismissed as being irrelevant to utilitarianism, and thus void of ethical content. Some of these objections can be met by reformulating Harsanyi’s theorem in the multi-profile context of Social Welfare Functionals theory. The present paper aims at showing that appropriately formulated single-profile variants of the theorem also meet the objections, and thus arguably make sense in terms of utilitarianism. More precisely, using an “enlarged” single-profile approach, we derive a Harsanyi-like representation which is both anonymous and compatible with meaningful comparisons of cardinal utility functions. These results depend on reformulating Harsanyi’s aggregation theorem in the social-choice theoretic framework of welfarism.

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