Tax systems and direct mechanisms in large finite economies

The equivalence of anonymous direct mechanisms and tax systems for continuum economies, which has been demonstrated by Hammond (1979) and Guesnerie (1981), is shown to have its counterparts in large finite economies.We are deeply indebted to Roger Guesnerie for stimulating our interest in this problem and for the inspiration gained through his work.     

Gains and losses at core allocations

The search for a coalition which can possibly improve upon a given allocation and the redistribution of endowments within such a coalition are conducted through the use of prices. Prices permit the expression of how much every agent gains or loses in the allocation. With any feasible allocation one can associate a price system such that either the total loss of all losers does not exceed a certain bound independent of the number of agents or the losers can improve. The definition of gains and losses that we use implies that the total gain is also bounded in core allocations. Our theorem is closely related to that of Vind (1965).     

Smoothing demand by aggregation with respect to wealth

We suggest in this paper to treat the problem of smoothing demand by aggregation in a two-step procedure, corresponding to the two different constituents of consumption characteristics, wealth and preferences. Instead of imposing a manifold structure on preferences we exploit the nice structure of wealth-space. The first step of this procedure, aggregation with respect to wealth, is carried out. It is shown that, for any preference, aggregation with respect to wealth yields a mean demand which is almost everywhere C¹. Moreover, it is shown that for an important class of preferences, vanishing Gaussian curvature of indifference surfaces does not destroy differentiability of the mean demand function.     

Endogenous Information Acquisition with Cournot Competition

This paper studies information production in a model where both entry of analysts and their optimal information quality is endogenous. We show existence of the Bayesian–Nash equilibrium and solve for it in closed form. The model displays rich behavior. In particular, we find that the precision of an individual signal will always be bounded from above by the precision of the prior belief on payoff uncertainty. Furthermore, we give examples that contradict the naive intuition about information acquisition. For instance, we show how a change in the cost structure that makes information cheaper decreases price informativeness, while at the same time market liquidity and the amount of resources society spends on information acquisition can change either way. The model gives a simple, fully rational explanation on why the number of analysts following a stock can be quite large. Endogenizing the cost of information by allowing the manager to choose an optimal informational policy, we find a variety of optima that depend discontinuously on the model parameters. As a consequence, among two similar firms, one may find it optimal to attract many analysts, the other will cooperate with only a few.I am greatly indebted to Antonio Bernardo and Avanidhar Subrahmanyam, whose support, encouragement, insight, and many valuable comments made this paper possible. In addition, I also thank Justin Chan, Sudipto Dasgupta, Jason Hsu, Martin Nielsen, and Elena Sernova, the editor and an anonymous referee.     

Modelling Policy Issues in a World of Imperfect Competition

General equilibrium theory constitutes a sound basis for the discussion of policy issues if firms do not have market power. However, if firms influence prices strategically, the concept of profits loses its meaning due to the price normalization problem. Hence, it is unclear how to model the behavior of oligopolistic firms. In order to provide a conceptual foundation for the analysis of policy issues in the case of imperfect competition, we discuss ways to formulate the objective of a strategic firm. In particular, we investigate the concept of real wealth maximization that is based on profits as well as on shareholders' aggregate demand.     

Profit maximization mitigates competition?

Summary. We consider oligopolistic markets in which the notion of shareholders’utility is well-defined and compare the Bertrand-Nash equilibria in case of utility maximization with those under the usual profit maximization hypothesis. Our main result states that profit maximization leads to less price competition than utility maximization. Since profit maximization tends to raise prices, it may be regarded as beneficial for the owners as a whole. Moreover, if profit maximization is a good proxy for utility maximization, then there is no need for a general equilibrium analysis that takes the distribution of profits among consumers fully into account and partial equilibrium analysis suffices.