Analysis of Purchase Decision Making: Network Externalities and Asymmetric Information

摘要

Product markets in which network externalities are present have been expanding through technological development. In such markets, information about users strongly affects purchase decision-making because a consumer's utility depends on the number of users. Although complete information is assumed in most studies of network externalities, it is difficult for consumers to obtain complete information in the real world. We construct a model of multiple-product market with network externalities. This model subsumes that each consumer has asymmetric information with respect to others' purchase decision-making. We analyze purchase decisions using game theory, multi-agent simulation, and experiments with human subjects. Results imply the following important features: (1) a monopolistic market arises when consumers neglect their own preferences and purchase the same products that others do; (2) a market becomes inefficient because of asymmetric information; (3) irrational decision-making might increase total surplus; and (4) much information does not always increase consumers' utilities.