城市规模是否提高了城市生产率

Dose the City Scale Improve the City Productivity

文章利用2003-2014年中国260个地级市面板数据,采用固定效应模型和分组回归方法实证检验了城市规模对城市生产率的影响,并进一步探讨了最优城市规模和城市化发展模式的选择问题。研究结论表明:城市规模扩大显著促进了城市生产率的提高,分地区回归中依然显著,但效应大小存在地区差异,表现为东部正向作用最大,中部其次,西部最小;二次项回归发现,城市规模与城市生产率之间存在显著的倒U型关系,说明城市规模扩张存在最优规模,这一最优值约为220万,分地区回归中这一关系依然显著,且统计显示,目前中国城市规模大部分位于最优值以下,城市规模增长还存在较大空间;按城市规模等级分组表明,大、中城市规模下,城市规模对城市生产率有显著的正向影响,小城市规模下正向作用不显著,特大城市规模下负向影响显著。这些结论为支持大、中城市发展提供了证据。

Using the panel data of 260 prefectural-level cities in China from 2003 to 2014,this paper tests the effect of cityscale on city productivity by using the fixed effect model and the method of grouping regression empirically. We further ex-plore the optimal city size and urbanization model selection problem. Research results show that：The city scale significantlypromotes the city productivity improvement,and the regional regression is still significant,but the effect exists regional differ-ences：a positive role in the eastern largest,followed by the central and western minimum. The quadratic regression analysisfound that there is a significant inverted U-shaped relationship between city size and urban productivity,indicating that the ex-istence of the optimal urban scale. The optimal value is approximately 250 million. The region regression in this relationship re-mained significant. Statistics show that most of China＇s city scale is lower the optimal value. The city scale is playing a role inpromoting city productivity. According to the grouping of city scale regression shows that the scale of large and medium-sizedcities has a significant positive effect on city productivity. There is no significant positive effect on the size of a small city. Andthe negative effect of mega cities size is not significant. These conclusions provide evidence for supporting the development oflarge and medium cities.