The Research on the Transformational Size and the Optimum Size of the Urban Agglomeration and Dispersion in China
以中国211个主要城市为样本，利用1989-2003年和2000-2005年面板数据，估计各城市的规模收益和外部成本，判断城市发展从集聚为主转向分散为主的转型规模。
This paper regards the 211 main cities as research samples,including 30 provincial capitals except for Lasa City,5 cities of planning individually and 176 prefectural metropolises in China,and sets up panel-data models of urban agglomeration and dispersion based on the successive time-series data from the year 1989 to 2003 and 2000 to 2005,to estimate relative returns to scale and external cost of each city respectively,then judges the phases of the cities development and seeks the city size that each city transforms from agglomeration as core to dispersion as core through comparing the relative returns to scale and external cost of each city. It is found by study that the other cities are in the phases of agglomeration except Shanghai,and in these cities,the growth of returns to scale in the majority of cities is faster than that of external cost.