Information Acquisition and Relative Efficiency of Competitive, Oligopoly and Monopoly Markets
分析当企业拥有关于随机市场需求的私人信息时，竞争均衡相对于古诺寡头和垄断均衡的效率。信息成本下，寡头和垄断企业可能因获取更多信息而带来更高预期福利。
This paper analyzes the relative efficiency of a competitive equilibrium against Cournot oligopoly and monopoly equilibria when firms have diverse private information about the stochastic market demand. When firms have information of the same precision, the competitive equilibrium yields a larger expected welfare. However, when information is costly, Cournot oligopoly and monopoly firms acquire more information and, hence, may yield a larger expected welfare than the competitive firms under certain conditions. The author also finds that competitive firms acquire less than the efficient level of information while Cournot oligopoly and monopoly firms may acquire more than the efficient level. Copyright 1995 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.