Abstract:

The world is uneven from the economic geography's point of view, and urban agglomeration evolves also unevenly. The development of urban agglomeration space is a process of increasing density, decreasing distance, and diminishing division/enhancing integration. Based on the 2009 annual report of the World Bank, this article builds a "density, distance, division" (3D) framework using new economic geography theory, and calculates and analyzes the spatial development state of cities in the Yangtze River Delta at the macro level. The results show that: (1) Urbanization mainly depends on increasing economic density; regional development mainly relies on overcoming the distance constraints; and regional integration depends on reducing segmentation and enhancing integration. Therefore "3D" constitute an appropriate framework to analyze the regional development and urban agglomeration integration process; (2) Shanghai, Suzhou, and Wuxi, where the local economy is more advanced, showed a 3D type of urban spatial development, while Changzhou and Nanjing, and Hangzhou exhibited the "density-distance" and "distance-division" 2D type of development, respectively. Nantong, Zhenjiang, Jiaxing, and Huzhou displayed a "distance" 1D type of development, while Shaoxing, Zhoushan, and Ningbo illustrated a "division" 1D type, and Yangzhou and other cities showed a 0D type of spatial development; (3) Economic density, psychological distance, manufacturing specialization index, and foreign direct investment have played important roles in labor productivity in the cities, while the distance factor was not significant, which indicates that increasing the density and strengthening the integration of internal and external resources are more important than shortening the distance between cities in promoting economic development in this region.

Key words: 3D framework, spatial pattern, labor productivity, Yangtze River Delta urban agglomeration, new economic geography