倒“U”型城市规模效率曲线及其政策含义——基于中国地级以上城市经济、社会和环境效率的比较研究

Inverted "U" Curve of Urban Scale Efficiency and Its Policy Implications——A Comparative Study on Economic,Social and Environmental Efficiency of Prefecture-level Cities and Above in China

关于城市规模问题在中国城市化进程中受到广泛关注,各种关于城市规模的理论和政策争论的焦点在于,城市规模效率与城市规模之间的倒"U"假说是否成立。本文利用数据包络分析(DEA)中的BCC模型、超效率模型和Tobit回归模型,系统测算和分析了中国城市和地级市及以上城市2005-2010年的规模效率及其与城市规模之间的关系。总体来看,中国城市规模效率与其规模正相关,地级市及以上城市经济、社会和环境规模效率与其规模基本上呈"倒U"型关系,倒"U"曲线顶点对应的城市规模对城市发展具有较强的政策含义。据此,本文提出"促进中小城市发展、限制超大城市、完善城市管理、协调区域城市发展"的政策思路。

Urban scale has received extensive attentions in the urbanization process in China. The debate of a variety of theories and policies focuses on whether the inverted ＂U＂ hypothesis of urban scale efficiency can be proved. This paper estimates and analyzes systematically the relationship of scale efficiency in Chinese cities at prefecture-level and above during 2005--2010, in BCC model, super-efficiency model and the Tobit regression model of data envelopment analysis （DEA）. The empirical results show that the efficiency of scale economies has a positive correlation with its size in Chinese cities. Economical, social and environmental scale efficiency at Prefecture-level （and above） cities had an inverted ＂U＂ relationship with its scale basically. The city size corresponding to the vertex of Inverted ＂ U＂ curve of the cities has a strong policy implication. Accordingly, the authors put forward some suggestions of policies and countermeasures to promote the development of small and medium-sized cities, limit the scale of large cities, improve city management and coordinate regional urban development.