产业组织理论系统地分析了市场结构对企业行为和市场运行效果的影响,并证明了在产业集中度、企业规模与利润率之间存在着正相关关系。但是,传统经济学认为,产业集中度提高必然会抑制竞争并导致垄断,而垄断则会降低资源配置效率。为解决这一矛盾,美国经济学家克拉克提出了旨在使规模经济与竞争活力相兼容的“有效竞争”市场结构模式,虽然至今还缺乏具有可操作性的衡 The theory of industrial organization systematically analyzes the influence of market structure on the behavior of enterprises and the effect of market operation and proves that there is a positive correlation between industrial concentration, firm size and profit rate. However, traditional economics believes that the increase of industrial concentration will inevitably curb competition and lead to monopoly, while monopoly will reduce the efficiency of resource allocation. In order to solve this contradiction, Clarke proposed the “effective competition” market structure model that aims to make scale economy compatible with competitive vitality. Although there is still a lack of an operational balance