多中心空间结构是否促进城市高质量发展?——来自中国地级城市层面的经验证据

Has the polycentric spatial structure promoted high-quality urban development? empirical evidence from prefecture-level cities in China

合理的城市空间结构是优化城市资源分配和推动城市高质量发展的必要条件。随着城镇化水平的提升和城市规模的扩大,城市空间结构逐渐由单中心向多中心转变,探索多中心空间结构对城市高质量发展的影响机制至关重要。基于2004—2019年的地级城市面板数据和Landscan高分辨率全球人口分布数据,探索多中心空间结构对城市高质量发展的影响机制,利用地形起伏度和明朝驿站获取的数据作为工具变量解决内生性问题,运用静态面板门槛模型探讨在不同阈值区间的城市规模在多中心空间结构对城市高质量发展过程中是否存在不同作用。此外,通过构建中介效应模型检验人口流动对多中心空间结构影响城市高质量发展的作用机制,并基于城市等级和地理区位进行异质性分析,通过去除副省级城市、替换被解释变量以及选取典型时间段等方式展开稳健性检验。研究结果表明:(1)多中心空间结构对城市高质量发展具有显著正向影响,城市空间结构的多中心程度提升有利于促进城市高质量发展。(2)多中心空间结构对城市高质量发展呈非线性关系,存在双门槛效应,随着城市规模的扩张,对于规模较大的城市而言,多中心空间结构会减弱对城市高质量发展的正向影响。(3)人口流动在多中心空间结构与城市高质量发展之间的关系中起到部分中介作用,中介效应显著。(4)相对于等级较低的城市,等级越高城市的多中心结构对城市高质量发展越具有负向影响;不同于东部地区,中西部地区城市多中心结构更有利于城市高质量发展。据此认为应在合理规划城市空间布局、遵循自身发展规律、确保中心城市的辐射带头作用、形成有序的城市发展布局规划等方面综合施策,为城市高质量发展提供保障机制。

A reasonable urban spatial structure is indispensable for optimizing the allocation of urban resources and promoting highquality urban development.With the development of urbanization and the expansion of urban scale,the spatial structure of cities gradually changes from monocentric to polycentric,and it is crucial to explore the influence mechanism of polycentric spatial structure on high-quality urban development.Based on the panel data of cities at prefecture-level and Landscan high-resolution global population distribution data from 2004-2019,this article explored the influence mechanism of polycentric spatial structure on urban quality development,used topographic relief data and data retrieved from ‘Ming Courier Stations’ as instrumental variables to address the endogeneity issue,and used static panel threshold models to explore the role of city size at different threshold intervals in polycentric spatial structure and whether there were different effects of city size at different threshold intervals on high-quality urban development.In addition,a mediating effects model was constructed to examine the mechanism of population mobility on the spatial structure of polycentric cities,a heterogeneity analysis was conducted based on city level and geographical location,and robustness tests were carried out by removing sub-provincial cities,replacing the explanatory variables,and selecting a typical time period.The results of the study showed that:(1) The spatial structure of urban polycentric cities had a significant positive impact on high-quality urban development,and the increase in polycentricity in the spatial structure of cities was conducive to such development.(2) The spatial structure of polycentric cities had a non-linear relationship with high-quality urban development,and a double threshold effect existed with the expansion of city size.The spatial structure of polycentric cities tended to weaken the positive impact on high-quality urban development.(3) Population mobility played a partly mediating role in the relationship between polycentric spatial structure and high-quality urban development,and the mediating effect was significant.(4) The polycentric structure of higher-level cities had a negative impact on high-quality urban development compared to lower-level cities.Unlike in the eastern region,the polycentric structure of cities in the central and western regions was more conducive to high-quality urban development.Accordingly,this article argues that comprehensive policies should be implemented in terms of rational planning of urban spatial layout,following the law of the development of cities themselves,ensuring the radiation leading role of central cities,and forming an orderly urban development layout plan.It is hoped that this study could provide policy insights for the implementation of the polycentric spatial development model in Chinese cities.