纵向差异下的连接外部性和网络结构分析

在寡头竞争的市场环境里,相互竞争的企业通常会与竞争对手建立连接,从而影响他们在产品市场上竞争的方式。本文我们建立两阶段博弈模型研究企业建立连接的激励以及由此而形成的网络结构形态。在博弈的第一期,具有纵向差异化的企业决定是否与其竞争对手建立连接;企业观察到连接结果后在第二期进行价格竞争。本文的分析显示均衡网络结构与连接效应、连接成本和消费者偏好有关,均衡网络可能仅是一个企业与其它所有企业建立连接的星型网络结构,也可能是没有任何企业建立连接的空网络结构。本文还分析了均衡网络和社会有效网络之间的关系,发现均衡网络和社会有效网络并不总是一致的,从社会计划者的角度看,企业建立连接可能存在激励不足,因此公共政策应该鼓励企业建立连接。

An Analysis of Link Externalities and Network Formation in Oligopolies with Vertical Differentiation

Competing firms often form links with their rivals,which can affect the way they compete in the product market.In this paper,we develop a model of a two-stage game to examine the incentives of the competing firms to form links and the resulting network structures of the link formation.In the first stage of the game,the firms with vertical product differentiation decide whether to form links with their rivals. After observing the network structure in the second stage,the firms compete in prices.Our analysis shows that,the equilibrium network structure is determined by the link effect,link costs,and consumers preferences.The equilibrium network structure is either a star network,in which one firm is directly linked to all other firms that are not linked to each other,or an empty network in which no link is formed.We also show thatas com pared with the socially optimal network,there are less links in the equilibrium network due to a lack of individual incentives in link formation.Public policy should be designed to encourage firms to form links.