Paul Champsaur

How to share the cost of a public good

The paper deals with a simple model with only one private and one public good. The core of such an economy is shown to have strong properties, in particular, it is stable in thevon Neumann-Morgenstern sense and complete. A natural candidate for a selection within the core is the concept ofLindahl equilibrium which constitutes a generalization of the concept of competitive equilibrium in an economy with private goods only. Although theLindahl equilibria belong in general to the core, they do not have the same symmetry properties. It is shown that it is possible to select in the core allocations having stronger symmetry properties than theLindahl equilibria.

Fair allocations in large economies

The purpose of this paper is the study of problems of equity in an economy with many agents. Conditions are given under which every equitable and Pareto optimal allocation is a competitive equilibrium with equal incomes for all agents. The results are also of potential relevance for the literature on incentive compatibility since the allocations that are obained through incentive mechanisms in large economies turn out to be equitable.

A Note on Incentives in Large Economies

Nash equilibria of anonymous and efficient mechanisms are studied in economies with a continuum of traders. Conditions are given under which some or all the Nash equilibria of such mechanisms yield competitive allocations. Particular attention is payed to the case of direct mechanisms where the truth constitutes a Nash equilibrium.

Strategic Behavior in Decentralized Planning Procedures

Noncooperative strategic behaviors are studied in the Malinvaud-Dreze-de la Vallee Poussin decentralized planning procedure. We depart from the assumption of myopic behavior by assuming that every agent takes into account the effect over a given period of time [0, T] of his answers to the Center. One shows that, for T large, every Nash equilibrium of the ensuing game in intertemporal strategies approaches: (i) a competitive equilibrium in an exchange economy, and (ii) a Lindahl equilibrium in an economy with public goods. Thus, the Center loses any significant influence on the income distribution.

On planning procedures which are locally strategy proof

We consider planning procedures which generalize the MDP procedure in the sense that, at each step, the planning bureau asks the agents their marginal rates of substitution, and uses the answers to revise the previously announced feasible programme. Such a procedure is “locally strategy proof” if, at each step, answering ones true marginal rate of substitution is the best myopic strategy for each agent. We give a general characterization of the family of locally strategy proof procedures and study its neutrality properties.

Concurrence par les prix et variété de produits

The literature provides two polar explanations for the variety of products of quantities offered on the market. Either this variety results from the number of firms, each of which supplies a single product or quality. Or else there is a monopoly offering a variety of products, that is, choosing its catalogue of goods in order better to exploit the diversity of its clientele. This article is a contribution to the development of an intermediary approach permitting an analysis of oligopoly situation without any a priori restriction on the variety of products by the individual firm.