网络外部性和规模经济性动态变化条件下的市场集中模式

把技术创新与成本的动态下降和消费者效用的动态上升联系起来,在网络外部性和规模经济性动态变化的基础上研究了市场集中模式和份额的演化。模型中反映了市场选择机制以及需求方和供给方的反馈机制,并得出了与以往静态研究不同的结论:①在一定的网络外部性强度和规模经济性强度的作用下,市场不仅会出现完全集中,也可能出现多厂商稳定共存的局面,还有可能出现市场的不稳定性;②厂商份额的演化结果与初始条件相关。消费者偏好和初始单位成本分布越不平均,市场的不稳定性越强,达到均衡值的时间越长。

Evolution of Market Share and Concentration with Network Externalities and Economies of Scale

Replicator dynamics and computer simulation techniques are used to construct a reduced form model which explores the evolution of market share by combining network externalities and economies of scale.Simulation results find that,first,network externalities and economies of scale shape the dynamic patterns of market concentration.Under certain conditions,monopoly emerges.Sometimes several firms co-exist or instabilities happen.This conclusion is different from other literatures.Second,the evolution of market share depends on the initial conditions.The higher the initial variance of costs and preferences,the longer it takes for market shares to reach an equilibrium value and concentration will be higher.The paper is of importance to understand the evolution of market structure within network economy.