There is ample evidence that emotions affect performance. Positive emotions can improve performance, while negative ones can diminish it. For example, the fears induced by the possibility of failure or of negative evaluations have physiological consequences (shaking, loss of concentration) that may impair performance in sports, on stage, or at school. There is also ample evidence that individuals have distorted recollection of past events and distorted attributions of the causes of success or failure. Recollection of good events or successes is typically easier than recollection of bad ones or failures. Successes tend to be attributed to intrinsic aptitudes or effort, while failures are attributed to bad luck. In addition, these attributions are often reversed when judging the performance of others. The objective of this paper is to incorporate the phenomenon that emotions affect performance into an otherwise standard decision theoretic model and show that in a world where performance depends on emotions, biases in information processing enhance welfare.

[This paper investigates the justification for the competitive assumption that consumers will act as price takers by considering the utility gain an individual can achieve by manipulating price formation through the use of non-competitive behavior. Although announcing one's competitive demand is generally not a best replay against the excess demand of the rest of the economy, we show that, as the number of consumers becomes large, the gain any one can achieve acting monopolistically goes to zero if the increase in numbers comes through replication or if the sequence of economies converges to an economy at which the equilibrium price correspondence is continuous.]

We analyze the problem in which agents have non-public information and are to play an asymmetric information game. The agents may reveal some or all of their information to other agents prior to playing this game. Revelation is via exogenously specified certifiable statements. The equilibria resulting from various revelation strategies are used to determine equilibrium revelation of information. Sufficient conditions are provided for complete revelation of all private information. A number of examples are provided illustrating when revelation will or will not occur in commonly analyzed games.

We develop an auction model for the case of interdependent values and multidimensional signals in which agents' signals are correlated. We provide conditions under which a modification of the Vickrey auction which includes payments to the bidders will result in an ex post efficient outcome. Furthermore, we provide a definition of informational size such that the necessary payments to bidders will be arbitrarily small if agents are sufficiently informationally small.

There has been a great deal of research in recent years investigating the question of whether or not there exist institutions (game forms) for which the set of equilibria will coincide with the set of Walrasian equilibria. In this paper we show the existence of a game form that is feasible, both for equilibrium and disequilibrium strategies, continuous, and for which the set of Nash equilibria coincides with the set of (constrained) Walrasian equilibria for all pure exchange economies. The game form allows agents to behave strategically both with respect to their preferences and their initial endowments.

In this paper we address the question of whether a price-setting monopolist can improve his welfare by imposing quantity constraints on buyers. We show first that if all buyers are identical, quantity rations are not useful for the monopolist. We then show by means of an example that if buyers are diverse, quantity rations may be desirable. It is shown that if there are only two commodities, the only constraint that may be useful to the monopolist is a zero constraint on one of the two commodities. An example shows that this property does not hold for more than two commodities.

We examine a general equilibrium model with asymmetrically informed agents. The presence of asymmetric information generally presents a conflict between incentive compatibility and Pareto efficiency. We present a notion of informational size and show that the conflict between incentive compatibility and efficiency can be made arbitrarily small if agents are of sufficiently small informational size.