Evolutionary stability and lexicographic preferences

We explore the interaction between evolutionary stability and lexicographic preferences. To do so, we define a limit Nash equilibrium for a lexicographic game as the limit of Nash equilibria of nearby games with continuous preferences. Nash equilibria of lexicographic games are limit Nash equilibria, but not conversely. Modified evolutionarily stable strategies (Binmore and Samuelson, 1992. J. Econ. Theory 57, 278–305) are limit Nash equilibria. Modified evolutionary stability differs from “lexicographic evolutionarily stability” (defined by extending the common characterization of evolutionary stability to lexicographic preferences) in the order in which limits in the payoff space and the space of invasion barriers are taken.     

Capacity constrained firms in (labor) markets with adverse selection

Summary. We discuss a competitive (labor) market where firms face capacity constraints and individuals differ according to their productivity. Firms offer two-dimensional contracts like wage and task level. Then workers choose firms and contracts. Workers might be rationed if the number of applicants exceeds the capacity of the firm. We show that under reasonable assumptions on the distribution of capacity an equilibrium in pure strategies (by the firms) exists. This result stands in contrast to the case of unlimited capacity. The utility level is uniquely determined in equilibrium. No rationing occurs in equilibrium, but it does off the equilibrium path. Received: December 29, 1999; revised version: November 30, 2000     

Limit-pricing as Bertrand equilibrium

Summary. We consider a Bertrand duopoly model with increasing returns to scale where one of the firms have a cost advantage and prices vary over a grid. We find that typically more than one equilibria exist. However, there are only two perfect equilibria. Moreover, as the size of the grid becomes small, both these equilibria converge to the limit-pricing outcome. Received: February 25, 2000; revised version: January 9, 2001     

Determinacy with nominal assets and outside money

Summary. We build a finite horizon model with inside and outside money, in which interest rates, price levels and commodity allocations are determinate, even though asset markets are incomplete and asset deliveries are purely nominal.Received: 2 July 2003, Revised: 1 December 2004 JEL Classification Numbers: D50, E40, E50, E58.Correspondence to: J. Geanakoplos     

Market clearing and derivative pricing

Summary. We develop a method of assigning unique prices to derivative securities, including options, in the continuous-time finance model developed in Raimondo (2001). In contrast with the martingale method of valuing options, which cannot distinguish among infinitely many possible option pricing processes for a given underlying securities price process when markets are dynamically incomplete, our option prices are uniquely determined in equilibrium in closed form as a function of the underlying economic data.Received: 14 April 2003, Revised: 7 January 2004, JEL Classification Numbers: G13, D52.This paper is dedicated to Birgit Grodal, whose strength and character we greatly admire. We are very grateful to Darrell Duffie, Steve Evans, Botond Koszegi, Roger Purves, Jacob Sagi, Chris Shannon, Bill Zame and an anonymous refereee for very helpful discussions and comments. The work of both authors was supported by Grant SES-9710424, and Andersons work was supported by Grant SES-0214164, from the National Science Foundation.     

Extensive-form games and strategic complementarities

I prove the subgame-perfect equivalent of the basic result for Nash equilibria in normal-form games of strategic complements: the set of subgame-perfect equilibria is a nonempty, complete lattice—in particular, subgame-perfect Nash equilibria exist. For this purpose I introduce a device that allows the study of the set of subgame-perfect equilibria as the set of fixed points of a correspondence. My results are limited because extensive-form games of strategic complementarities turn out—surprisingly—to be a very restrictive class of games.     

基于地下经济行为的博弈分析

第二次世界大战以后,经济学家在对传统经济进行反思的过程中,开始从地下经济角度来解释现实经济现象中宏观经济预测的偏离及菲力普斯曲线开始向上和向外盘旋现象。地下经济一般被认为是由那些企业或个人防止和逃避政府的管制、税收和监察的经济活动和由此获得的收入构成的。根据政府作为政策制定者和观察者及受调查者即企业或个人之间的关系,本文提供了一个相互作用系统的样板,通过政府和企业及个人之间在交税行为过程中产生的信号传递反馈系统,拟用一种不完全信息的动态博弈分析方法,论证得出信息系统的完整化、公开化、政府法律政策严明性及政府的相机抉择制度对社会经济发展的重要作用。     

贸易自由化与贸易保护的均衡博弈

中国在改革开放以后贸易保护政策的演进更有其独特的背景和转型国家的特殊性,梳理其演进和变化的路径对未来我国贸易政策的合理性和有效性都可以提供必要的理论支撑。贸易政策是根据本国经济发展的阶段在贸易自由化和贸易保护之间进行理性选择的结果。     

基于博弈理念构建和谐税收制度的基本思路

本文阐述了和谐税收制度对建设和谐社会的重要性,指出和谐的税收制度应是一种纳什均衡的制度.运用博弈理念,从税种结构博弈均衡、税收负担博弈均衡、税收征管博弈均衡及稽查监督博弈均衡四个方面给出构建和谐税收制度的基本思路.     

制度与经济增长

以诺斯为代表的新制度经济学把制度因素引入到经济增长理论之中,并认为制度是经济增长的决定因素,从而打破了新古典经济增长理论制度既定的假设条件,使经济增长理论更趋成熟和完善。但制度对经济增长起主要作用是有条件的,即在制度不均衡的条件下,制度对经济增长起主要作用,而在制度均衡的条件下,对经济增长起主要作用的是技术而不是制度。