Urban Diversity and Economic Growth
探讨城市多样性如何通过影响消费和生产的外部效应促进经济增长，并回顾了规模经济、共享投入与交易成本节约以及大数定律在大都市区的作用，对城市经济学研究者有参考价值。
This paper considers the heterogeneity and diversity of cities as sources of economic growth. It links modern notions of economic growth to the distinguishing characteristics of cities and to the external effects on consumption and production produced by the internal diversity of urban areas. The paper reviews the role of traditional scale economies as well as the importance of diversity in economizing on shared inputs and transactions costs, and efficiencies arising from the operation of the law of large numbers in metropolitan areas. The authors also review recent empirical evidence on the importance of these elements of heterogeneity in conditioning economic growth.