引言对称信息和不对称信息是信息经济学中两个相互对应的概念。对称信息是指在某种相互对应的经济人关系中,对应双方都掌握有对方所具备的信息度量;而不对称信息则指在经济人之间不作对称分布的有关某些事件的知识或概率分布。目前,人们越来越相信市场中存在着不完善的发展因素 Introduction Symmetric information and asymmetric information are two mutually corresponding concepts in information economics. Symmetric information refers to the fact that both parties hold the information measure that each other has in some kind of mutual economic man and the asymmetric information refers to the knowledge or probability of certain events that are not symmetrically distributed among economic persons distributed. At present, people are increasingly convinced that there are imperfect development factors in the market