| Abstract | Electronic market has become the most important exchange intermediary in national economy. Searching capacity, gathering scale and market efficiency are three key factors that can reflect character and economic law of electronic market. Base on theory of search, this paper introduce probability density function to construct a three-variety model including matching capacity, market scale and efficiency of electronic. For understanding action mechanism of electronic market, this model depicts influences that matching capacity, market scale impose on efficiency of electronic market, and relation between matching capacity and market scale. This research shows that: (1)On the one hand, searching improves efficiency of electronic market by enlarging market scale and increase effective range of market competition. It embodies effect of activity; On he other hand, searching can change distribution function of transaction opportunities, and reduce unsymmetrical information so as to improve efficiency of electronic market. (2)Comparative advantage of electronic market in matching capacity will lead it to occupy efficiency space of other electronic markets. It is embodiment of crowding-out effect. (3)The optimum market scale determined by matching capacity which influenced by negative externality of market. So the maximum efficiency of electronic market is the equilibrium between matching capacity and market scale. |