差别产品的动态完全竞争

现有经济学理论认为完全竞争是社会福利达到最大的市场结构，但完全竞争又只在每个厂商都生产同质产品时出现。对异质的差别产品来说，这个论断存在着内在矛盾：产品差别化更符合消费者的需求偏好，但不利于实现社会福利最大。随着市场格局从卖方市场向买方市场、社会生产从大规模制造向规模定制的剧烈转变，上述矛盾变得愈加突出。本文通过引入需求方市场结构及其特征的概念，构建了供求互动的市场结构演化模型，结果发现在收入增长、资本积累和技术进步的共同持续充分作用下，供求双方内部都会趋向基于差别产品的动态完全竞争。

Dynamic Perfect Competition with Differentiated Products

Mainstream economic theory affirms that perfect competition is the market structure with maximized social benefit and presents only when every firm sells homogeneous products. But for non-standardized products,there is a paradox within the above affirmation. That is,differentiated products meet the preference of consumer better than homogeneous products but make the firms producing them not to price at their marginal costs. As the emerging of buyer's market and mass customization,the above paradox is becoming more and more notable. The paper conceived the basic evolutionary mechanisms of market structure with supply-demand interaction by introducing the concept of demand-side market structure and matching supply-side market structure with demand-side market structure. It results that dynamic perfect competition will be tended to within both sides based upon differentiated products as long as the growth of income,the accumulation of capital and the progress of technology play their roles persistently and sufficiently at the same time.