博弈与社会.ppt

《博弈与社会》导论:个人理性与社会效率 张维迎 教授 北京大学光华管理学院 本章目录 社会问题； 理性人行为； 效率标准； 外部性与科斯定理。 社会的两个基本问题 社会是什么？ 协调（coordination) 合作（cooperation) 协调问题：以交通为例 协调与预测 协调问题的核心是预测（prediction)： 预测其他人如何行为； 个人行为的基本规则是什么？ 信息：too little knowledge; too much knowledge; fail to use the knowledge; no knowledge can help. 合作与激励 合作问题的核心是激励(incentive) 个人行为与社会利益的冲突 什么是个人的最优选择？ 什么是社会的最优选择？ 如何把个人行为与社会利益统一起来？ 协调与合作相互作用 如交通问题； 如密云元宵节惨剧； 如SARS问题，禽流感问题； 如恐怖主义问题； 如股票市场； 如宏观经济波动； 等等。 社会问题及其解决办法 社会规模：小社会，大社会，全球化； 技术问题： 社会分工： 社会制度：个人的行为规则 正式制度；明规则，法律 非正式制度；潜规则，社会规范，文化 价格制度； 非价格制度。 理解人的行为 所有社会科学都是有关人的行为的科学，但不同学科的方法、假设、着眼点不同； 经济学：从个人到社会(from micro to macro) 社会学：从社会到个人(from macro to micro) 心理学：用观察、实验的方法看人们实际上是怎么行为的。（行为科学） Homo economicus vs. Homo sociologicus Adam Smith vs. Emile Durkheim Rational, outcome-oriented; social norm-oriented, not outcome-oriented: “the former is supposed to be guided by instrumental rationality, while the behavior of the latter is dictated by social norms. The former is ‘pulled’ by the prospect of future rewards, whereas the latter is ‘pushed from behind by quasi-inertial forces. Cont’ The former adapts to changing circumstances, always on the lookout for improvement. The latter is insensitive to circumstances, sticking to the prescribed behavior even if new and apparently better options become available. The former is easily caricatured as self-contained, asocial atom, and the latter as the mindless playing of social forces.” (Jon Elster, 1989, JEP) 为什么学习博弈论？ 博弈论是有关“互动行为”(interactive behavior)的科学 “A sort of umbrella, or unified field theory for the rational side of social science. It develops methodologies that apply in principle to all interactive situations.”(Aumann and Hart, 1992) “It provides solid micro-foundations for the study of social structure and social change.”(Jon Elster, 1982) Cont’d “Nash Equilibrium has had a fundamental and pervasive impact in economics and the social science which is comparable to that of the discovery of the DNA double helix in the biological sc