A weak bargaining set for contract choice problems

In this paper, we consider the problem of choosing a set of multi-party contracts, where each coalition of agents has a non-empty finite set of feasible contracts to choose from. We call such problems, contract choice problems. The main result in this paper states that every contract choice problem has a non-empty weak bargaining set. The need for such a solution concept which is considerably weaker than the core arises, since it is well-known that even for very simple contract choice problems, the core may be empty. We also show by means of an example that an analog of the bargaining set due to Mas-Colell [Mas-Colell, A., 1989. An equivalence theorem for a bargaining set. Journal of Mathematical Economics 18, 129–139], as well as the natural analog of the bargaining set due to Aumann and Mashler [Aumann, R., Maschler, M., 1964. The bargaining set for cooperative games. In: Dresher, M., Shapley, L., Tucker, A. (Eds.), Advances in Game Theory. Princeton University Press, Princeton, NJ] may be empty for contract choice problems.     

Existence of Nash networks in one-way flow models

This paper addresses the existence of Nash equilibria in one-way flow models in a number of different settings. In these models players form costly links with other players and obtain resources from them through the directed path connecting them. We find that heterogeneity in the costs of establishing links plays a crucial role for the existence of Nash networks. The paper also provides conditions for the existence of Nash networks in models where costs and values of links are heterogeneous. We would like to thank an anonymous referee for useful suggestions. We would also like to thank Hans Haller and participants at the AEA Meetings 2007 for helpful comments. Sudipta Sarangi acknowledges the support of NSF grant HSD-0527315 and the hospitality of CREUSET, Jean Monnet University.     

军队油料保障链柔性及其在汶川抗震救灾中的运用

基于供应链理论,对军队油料保障链、军队油料保障链预柔性等概念作了定义,阐述了军队油料保障链柔性的含义,提出了军队油料保障链柔性的创造途径。同时,结合军队参加"5.12"抗震救灾行动,对军队油料保障链柔性的运用及获得的效果进行了分析。     

Imperfect recall and the relationships between solution concepts in extensive games

Summary. In a game of imperfect recall, a sequential equilibrium may not be a Nash equilibrium, and a perfect equilibrium may not be a sequential equilibrium. Sufficiency conditions weaker than perfect recall are given to ensure the standard relationships hold between perfect equilibrium, sequential equilibrium and Nash equilibrium.Received: 22 October 2003, Revised: 18 November 2003, JEL Classification Numbers: C72.     

What do uncertainty-averse decision-makers believe?

Summary. This paper introduces the concept of firm belief, which is proposed as a new epistemic model for a wide class of preferences. In particular, firm beliefs are shown to have the following desirable properties: (i) they are derived from preferences according to a plausible rule of epistemic inference; (ii) they satisfy standard logical properties; and (iii) tractable representations of firm belief are available for all (suitably continuous) biseparable preferences [13, 14], including the Choquet expected utility [30] and maxmin expected utility [16] classes. We also use firm belief to construct a generalization of Nash equilibrium for (two-player) normal form games. Received: December 14, 1999; revised version: February 26, 2001     

Cycling in a stochastic learning algorithm for normal form games

In this paper we study a stochastic learning model for 2×2 normal form games that are played repeatedly. The main emphasis is put on the emergence of cycles. We assume that the players have neither information about the payoff matrix of their opponent nor about their own. At every round each player can only observe his or her action and the payoff he or she receives. We prove that the learning algorithm, which is modeled by an urn scheme proposed by Arthur (1993), leads with positive probability to a cycling of strategy profiles if the game has a mixed Nash equilibrium. In case there are strict Nash equilibria, the learning process converges a.s. to the set of Nash equilibria.     

Nash equilibrium when players account for the complexity of their forecasts

Nash equilibrium is often interpreted as a steady state in which each player holds the correct expectations about the other players' behavior and acts rationally. This paper investigates the robustness of this interpretation when there are small costs associated with complicated forecasts. The model consists of a two-person strategic game in which each player chooses a finite machine to implement a strategy in an infinitely repeated 2×2 game with discounting. I analyze the model using a solution concept called Nash Equilibrium with Stable Forecasts (ESF). My main results concern the structure of equilibrium machine pairs. They provide necessary and sufficient conditions on the form of equilibrium strategies and plays. In contrast to the “folk theorem,” these structural properties place severe restrictions on the set of equilibrium paths and payoffs. For example, only sequences of the one-shot Nash equilibrium can be generated by any ESF of the repeated game of chicken.     

An equilibrium approach to international merger policy

I treat international merger policy as a repeated veto game. I show that there exists a unique efficient equilibrium within a particular class of trigger strategy equilibria. I then consider a series of comparative statics and extensions: (a) if for some exogenous reason one of the countries becomes more lenient towards mergers, than the other country becomes more lenient as well; (b) merger remedies increase the probability that a merger is approved and increase total welfare; (c) the effects of a merger wave are magnified by the equilibrium approval policy.     

供应链管理的蛙鸣博弈分析

本文认为,蛙鸣博弈与供应链管理具有相似性,将其应用于描述供应链管理合作问题,可以得出互补是供应链企业合作的基本前提;市场是解决合作与竞争矛盾的关键;“双赢”是供应链企业合作的结果。文章提出,企业加盟供应链战略联盟,必须学会与其他企业进行合作,建立相互间信任机制,优化信息沟通渠道,实现信息充分共享,消除冲突,协调一致,以保证供应链整体决策的优化,提升供应链的整体竞争力,并进而提高企业的综合竞争力。     

论体育游戏与培养学生人文精神

本文从实施学生素质教育的要求,论述了体育游戏作为身体文化和社会文化的一部分,在促进人的全面发展中所具有的特殊功能,尤其是在现代人文主义教育思想的影响下,体育游戏应从强调技术学习中解放出来,大大突出其人文性,注重其对学生人文精神培养的地位和作用。并针对当前学校体育游戏教学的实际情况,提出了在游戏教学中培养学生人文精神的观点和要求。