The traditional and representative industrial cluster theories include Marshall's External Economy Theory, Krugman's Scale Reward Theory, and Porter's Diamond Model Theory, etc.
传统的具有代表性的产业集群理论包括马歇尔的外部经济论、韦伯的集聚经济论、克鲁格曼的规模报酬理论、波特的钻石模型理论等。
First of all, this paper reviews the industrial cluster external economy effect theory; offer the theoretical foundation for subsequent comparative study and analysis.
首先，本文回顾了产业集群外部经济效应理论，为后续的比较研究和分析提供理论基础。
This paper discussed the principle of externality in the domain of urban wastewater reuse, analyzing the external economy of urban wastewater reuse with the theory of economics.
文章运用经济学理论分析了城市污水资源化的外部经济性。
应用推荐