A Game Theoretical Analysis of Cooperation and Coalition Formation

本研究的目的是运用博弈论的新方法，探讨追求自身价值的经济主体之间自愿合作和联盟形成的条件和机制。本研究包括以下三个关于自愿合作和联盟形成的主题。(1)非合作谈判模型的合作和联盟的形成我们提出了一个非合作的顺序谈判模型的一般n人的战略游戏，其中合作的一组球员可能会导致外部性的其他球员。我们首先定义了一个新的概念的核心，称为纳什核心，n人战略博弈。纳什核心的定义是一个新的概念的有效性的支付分配，这是基于这样的想法，当一个联盟的形式，一个回应，恭维联盟应该是一致的纳什谈判解决方案的谈判。我们证明了谈判模型的最大局中人组在平稳子博弈中形成完美均衡当且仅当博弈的Nash谈判解属于Nash核心。此外，谈判结果的纳什讨价还价的解决方案的结果。我们设计并进行讨价还价的实验，以测试理论预测。我们发现，讨价还价的联盟形成的结果有很大的影响，互惠行为的主体。(2)群体形成的演化分析我们提出了一个群体形成的演化博弈模型，在集体行动问题，并探讨如何异质偏好影响长期均衡的群体形成。(3)经济应用我们将研究中建立的理论模型应用于京都议定书中关于气候变化的国际谈判。本文以欧盟、前苏联、日本和美国的实际排放数据为基础，研究了非合作谈判模型如何解释京都议定书中达成的CO2减排量。

The aim of this research is to investigate conditions and mechanisms for voluntary cooperation and coalition formation among economic agents pursuing their own values, by applying new methodologies in game theory. The research consists of the following three topics about voluntary cooperation and coalition formation.(1) noncooperative bargaining models for cooperation and coalition formationWe present a noncooperative sequential bargaining model for a general n-person strategic game where cooperation by a group of players may induce externality to other players. We first define a new notion of the core, called the Nash core, of the n-person strategic game. The Nash-core is defined by a new notion of effectiveness of a payoff allocation, which is based on the idea that when a coalition forms, a response by, the compliment coalition should be consistent with the Nash bargaining solution of their negotiations. We prove that the largest group of players forms in a stationary subgame perfect equilibrium of the bargaining model if and only if the Nash bargaining solution of the game belongs to the Nash core. Moreover, negotiations result in the Nash bargaining solution outcome. We design and conduct bargaining experiments to test theoretical predictions. We show that bargaining outcomes of coalition formation are substantially influenced by reciprocal behavior of subjects.(2) evolutionary analysis of group formationWe present an evolutionary game model for group formation in the collective action problem and investigate how heterogeneous preferences affect a long-run equilibrium for group formation.(3) economic applicationsWe apply theoretical models developed in the research to international negotiations on climate change in the Kyoto protocol. We investigate how noncooperative bargaining models can explain the C02 emissions reduction agreed in the Kyoto protocol, based on actual data about emissions by EU, Former Soviet Union, Japan and USA.