人口向小城市集聚更节约公共成本吗

Will People's Moving to Small Cities Save More Public Cost?

本文使用2004-2014年中国城市面板数据,通过比较不同规模城市间公共支出的人口规模弹性,分析了城市规模对城市公共支出规模效应的影响。实证研究发现,城市人口增长带来的公共支出增长弹性远小于1,即人口增长并不等比例带来公共支出的增长,说明城市公共支出具有较强的规模效应。研究还发现,在人口增长过程中大城市的公共支出弹性平均仅为小城市的1/2,表明大城市公共支出的规模效应强于小城市。进一步分析发现,人口集聚程度和外来人口因素会通过不同机制来降低城市公共支出的人口规模弹性,并且这种机制在大城市中表现得更为明显。上述结论在考虑内生性问题以及进行相关稳健性检验的情况下依然成立。大城市在公共支出方面具有更高的规模效应,即使在考虑大城市人均公共成本较高的情况下,大城市在吸纳新增人口方面也更具成本优势,因此鼓励人口向小城市集聚可能会耗费更多的公共成本。

In this paper, we compare the population scale elasticity of the public expenditure between different-sized cities using the data of cities in China from 2004 to 2014, and analyze the effect of city size on the scale effect of public expenditure. Our results show that the public expenditure elasticity with the growth of urban population is far less than 1. That is to say that the increase of public expenditure is not in equal proportion with the growth of urban population. This shows that the urban public expenditure has a relatively strong scale effect. We also find that, in the course of the population growth, the public expenditure elasticity of big cities is only 1/2 of that of the small cities. This shows that the scale effect of public expenditure in big cities is much stronger than small cities, and this scale effect increases with the growth of the size of the city. Further analysis shows that the degree of population agglomeration and migrants＇ factors will reduce the size of urban public expenditure by different mechanisms, and these mechanisms are more obvious in big cities. Above conclusions are still robust in the case of considering variable endogeneity, substituting the explanatory variables and the core explanatory variables, as well as the control of regional public service differences. This paper argues that since big cities have stronger scale effect in terms of public expenditure, even in the case of large cities with higher per capita public cost, encouraging the population agglomeration to small cities will spend more public cost.