UNIQUENESS OF EQUILIBRIUM PAYOFFS IN FINITELY REPEATED GAMES WITH IMPERFECT MONITORING*

This paper examines when a finitely repeated game with imperfect monitoring has a unique equilibrium payoff vector. This problem is nontrivial under imperfect monitoring, because uniqueness of equilibrium (outcome) in the stage game does not extend to finitely repeated games. A (correlated) equilibrium is equilibrium minimaxing if any player's equilibrium payoff is her minimax value when the other players choose a correlated action profile from the actions played in the equilibrium. The uniqueness result holds if all stage game correlated equilibria are equilibrium minimaxing and have the same payoffs. The uniqueness result does not hold under weaker conditions.     

A SIMPLISTIC GENERAL EQUILIBRIUM THEORY OF CORRUPTION

The author's simplistic view of corruption is that all politicians and government officials—like everyone else—are constrained self-maximizers. They therefore establish or maintain regulations and controls with the intent to facilitate corruption, which then becomes a source of income for them. Under private enterprise, where resources are transferable and movable, competition limits the ability to corrupt. However, in state enterprises, limiting corruption through competition is difficult. Corruption can help offset the inefficiencies of a communist or hierarchical system, as the economy makes a transition toward private property. But the danger is that corruption will become institutionalized and develop well-defined, transferable rights. Once that happens, the economy gets stuck there, as it has in India. Thus, in reforming a communist system—as that of China—into a private property system, gradualism will not do.     

EQUILIBRIA IN NON-COOPERATIVE GAMES II: DEVIATIONS BASED REFINEMENTS OF NASH EQUILIBRIUM

In any Nash equilibrium no player will unilaterally deviate. However, many games have multiple Nash equilibria. In this paper, we survey some refinements of Nash equilibria based on the hypothesis that any player may consider a deliberate deviation from a Nash equilibrium vector while expecting other players to respond optimally to this deviation. The concepts studied here differ in the expectations players have about other players' responses to a deviation. This sort of deviations philosophy is predicated on the thought process of players. Therefore, the validity of a particular equilibrium concept to an economic model may depend upon the relevance of the thought process implied by the concept.     

EQUILIBRIA IN NON-COOPERATIVE GAMES I: PERTURBATIONS BASED REFINEMENTS OF NASH EQUILIBRIUM

The concept of Nash equilibrium is widely used to analyse non-cooperative games. However, one of the problems with that concept is that many games have multiple equilibria. Recent work has concentrated on reducing or refining the set of Nash equilibria in some games. In this paper, we survey some equilibrium concepts based on perturbations of strategies that refine the set of Nash equilibria. We discuss the pros and cons of each concept and its relationship to the others by the use of numerous examples and intuition. It is hoped that this survey will enable the economist to consider the relevance of a particular equilibrium concept to a given economic model of interest. Journal of Economic Literature Classification Number: C72.     

MIDDLEMEN IN SEARCH EQUILIBRIUM*

This article shows how allowing for goods to be divisible at the point of consumption and incorporating productive heterogeneity lead to the emergence of middlemen in an equilibrium search environment. In the baseline model, middlemen are welfare reducing and their number increases as market frictions are reduced. When the model is extended to allow for time taken in production and increasing returns to scale in the market meeting technology, middlemen can be beneficial to society by speeding up the meeting process.     

THE EXISTENCE OF EQUILIBRIUM IN A DIFFERENTIATED DUOPOLY WITH NETWORK EXTERNALITIES*

The existence of a pure‐strategy subgame‐perfect equilibrium in qualities and prices is investigated in a duopoly model of vertical differentiation where quality improvements require a quadratic variable cost and network externalities operate. We show that there exists a parameter region where the incentive to predate at the quality stage prevents firms from reaching a pure‐strategy non‐cooperative equilibrium with prices above marginal costs. If network externalities are sufficiently large, a Bertrand equilibrium with zero profits may arise, although the amount of product differentiation is strictly positive.     

ENDOGENOUS TIMING IN MULTI-STAGE DUOPOLY GAMES*

This paper presents an investigation of the endogenous timing in multi-stage duopoly games in which duopolists choose two variables over two periods. The paper elaborates the two-stage strategic commitment game discussed by Brander and Spencer (1983). Duopolists decide their outputs and cost-reducing investments and they are allowed to choose which action to take first. The paper discusses two types of games; one is a three-stage game in which each duopolist can commit to the order of choices before it chooses its output or cost-reducing investments, and the other is a two-stage game in which it cannot. The paper finds that at least one firm chooses its output first. Furthermore, the three-stage game has the unique equilibrium outcome in which both firms choose their outputs first.     

THE DISTRIBUTION OF MONEY AND PRICES IN SEARCH EQUILIBRIUM*

This article considers a search‐theoretic model of monetary exchange. Agents bargain over both the amount of money and the quantity of goods to be exchanged in bilateral meetings, determining endogenously the distributions of money and of prices. I show that money is neutral if changes in the money supply are accomplished via proportional transfers. However, within the class of lump‐sum transfers, an increase of the rate of monetary expansion tends to decrease the dispersion of wealth and prices and to improve welfare when inflation is low; but when inflation is high enough, the opposite effects occur.     

ON THE INEFFICACY OF TEMPORARY POLICY IN A DYNAMIC GENERAL EQUILIBRIUM WITH MONEY*

We construct a dynamic economy with many consumers with money in their utilities. Two main results—a turnpike theorem and inefficacy of temporary policy—are established in a dynamic general equilibrium framework in which price effects generated through markets are explicitly factored in. Turnpike, which is perfectly independent from wealth distribution among the heterogeneous consumers, will be globally attractive. Temporary policy is not effective not only for the future but for the current economy if the long‐run interest rate level is low. The inefficacy result coincides with an intuitive explanation by the standard permanent income hypothesis.     

A THEORY OF MONEY AND MARKETPLACES*

This article considers an infinitely repeated economy with divisible fiat money. The economy has many marketplaces that agents choose to visit. In each marketplace, agents are randomly matched to trade goods. There exist a variety of stationary equilibria. In some equilibrium, each good is traded at a single price, whereas in another, every good is traded at two different prices. There is a continuum of such equilibria, which differ from each other in price and welfare levels. However, it is shown that only the efficient single‐price equilibrium is evolutionarily stable.     

EQUILIBRIUM GROWTH IN A MONETARY ECONOMY WITH TRANSACTIONS COSTS*

The paper describes a dynamic general equilibrium monetary economy with technological primitives that are consistent with the possibility of asymptotic equilibrium growth. The paper focuses on the relationship between equilibrium financing constraints on investment goods, transaction costs and economic growth. A generalized growth condition is derived that involves both monetary growth rates and transaction costs. The condition is used to show that (i) although inflation taxes can potentially exert a negative influence on long-run economic growth, these growth effects cannot in general be arbitrarily large; and (ii) for some monetary growth rates, money is superneutral in contrast to the models of Stockman and Abel. Numerical work indicates that although the welfare and growth effects of decreasing nominal interest rates from a benchmark are large, the costs associated with raising nominal interest rates from benchmark are not.     

A SIGNALING THEORY OF GRADE INFLATION*

When employers cannot tell whether a school truly has many good students or just gives easy grades, a school has incentives to inflate grades to help its mediocre students, despite concerns about preserving the value of good grades for its good students. We construct a signaling model where grades are inflated in equilibrium. The inability to commit to an honest grading policy reduces the efficiency of job assignment and hurts a school. Grade inflation by one school makes it easier for another school to do likewise, thus providing a channel to make grade exaggeration contagious.     

A HIERARCHICAL THEORY OF THE FIRM*

This paper provides a mathematically coherent and concise formulation of the Williamson market-failure approach and, hence, develops models for single-level and multilevel firms and organizations. These models optimally determine the extent of integration for each viable link on every hierarchical level, When the models are reformulated in terms of four operational parameters that determine integration, applied benefit-cost methods can be utilized, in practice, to model a firm. Both static and dynamiclmodels-are presented.