On Vertical Mergers and Their Competitive Effects
构建了纵向合并的均衡理论，分析上游生产者与下游竞争对手在投入品市场的策略行为，发现合并既带来效率提升也产生合谋效应，并可用产品差异化指标判断对消费者的影响。
It is well known that vertical integration can change an upstream producer's incentive to supply the integrated …rm's downstream rivals.However, it has not been noticed that vertical integration also changes these rivals' incentives to choose suppliers.This paper develops an equilibrium theory of vertical merger that incorporates strategic behaviors in the input market of both the integrated …rm and the (downstream) rivals.Under fairly general conditions, vertical mergers will result in both e¢ciency gains and a collusive e¤ect, and a familiar measure concerning product di¤erentiation can be used to evaluate whether a vertical merger tends to bene…t or harm consumers.