Asymmetric Information

本项目研究的是信息不对称的经济体。它由三部分组成。第一部分建立了研究主体信息不完全时市场的一般框架。建立了agent具有私有信息的一般均衡模型。采用了一种衡量经济主体所掌握信息重要性的新方法。该项目建立了一个条件，在这个条件下，大量的代理人可以改善由于不对称或私人信息的存在而导致的低效率。它研究了在多大程度上，同时近乎有效和激励相容的结果可以成为市场的结果。第二部分考察了在个人估值为人所知、个人不能被迫参与的环境中开展项目的问题。最后一节探讨了在玩贝叶斯游戏之前允许交流的效果。大多数对信息不对称博弈的分析都忽略了这种可能性。允许交流可以扩大均衡集，如果使用贝叶斯-纳什均衡的改进，可以缩小预测结果集。这个项目应该得到支持，因为解决的问题很重要。第一部分对具有私有信息的主体一般均衡模型的研究可以为不同的不完全信息理论提供一个统一的框架。这类研究的初步结果发现，在拥有大量经济主体的经济体中，即使是少量的私人信息也会导致令人惊讶的巨大低效。第二部分应该对许多问题提供有用的见解，在这些问题中，一个群体必须采取集体行动，并分配行动的个人成本或收益。这类问题最普遍的例子是是否进行一个公共项目，如果进行，项目的成本如何在小组成员之间分配。第三部分扩展了贝叶斯博弈论，允许在玩游戏之前进行交流。这一点很重要，因为贝叶斯博弈模型几乎被用于经济学的每个部分，用来对代理可能拥有不同信息的问题进行建模，研究者的初步结果表明，游戏前的交流对贝叶斯博弈的结果有非常重要的影响。

This project deals with economies in which there is asymmetric information. It consists of three parts. The first part develops a general framework for the study of markets when agents have imperfect information. A general equilibrium model is developed in which agents have private information. A novel measure is used of the significance of the information held by economic agents. The project establishes the conditions under which a large number of agents ameliorates the inefficiencies due to the presence of asymmetric or private information. It investigates the extent to which outcomes which are simultaneously nearly efficient and incentive compatible can be outcomes of markets. The second part examines the problems of undertaking projects in environments in which individuals' valuations are privately known and individuals cannot be forced to participate. The last section explores the effect of allowing communication prior to the play of a Bayesian game. Most analyses of games with asymmetric information ignore this possibility. Allowing communication can expand the set of equilibria and, if refinements of Bayes-Nash equilibria are used, can shrink the set of predicted outcomes. This project should be supported because the issues addressed are important. The research in the first part on general equilibrium models of agents with private information could provide a unifying framework for the different theories of imperfect information. The preliminary results from this line of research find that even a small amount of private information can cause surprisingly large inefficiencies in economies with large numbers of economic agents. The second part should provide useful insights into the many problems in which a group has to take a collective action and allocate individual costs or benefits of that actions. The most pervasive example of such a problem is whether to undertake a public project and, if undertaken, how the costs of the project are to be distributed among the members of the group. The third part extends Bayesian game theory by allowing communication prior to the play of the game. This is important because Bayesian game models are used in nearly every part of economics to model problems in which agents may have different information and the preliminary results by the investigator show that pre-play communication can have a very significant effect on the outcome of the Bayesian game.