人口流动、知识关联与城市创新——基于空间溢出与距离约束视角

Population Mobility,Knowledge Relevance and Urban Innovation:Based on Spatial Spillover and Distance Constraints

随着人口负增长程度不断加深,流动人口成为未来城市人力资本竞争的关键,也成为推动城市创新发展的核心动力,多视角探究人口流动对城市创新发展的影响具有重要的理论与现实意义。运用空间经济学框架下的知识创新与扩散模型(TP模型),利用2010~2021年中国283个地级市的面板数据,结合空间计量模型方法,基于空间溢出与地理距离约束双重视角,研究人口流动对城市创新水平的影响效应。研究发现:(1)城市创新存在明显的空间关联与集聚特征,具体表现为东部沿海地区“高高集聚”,东北部、西部、西南部等内陆地区“低低集聚”。(2)人口流动规模扩大强化了知识关联进而对城市创新水平产生显著的促进作用。空间效应分解发现,人口流动对城市创新发展具有空间溢出效应,人口在空间上的自由流动可以产生区域创新发展的知识溢出与扩散效应。(3)人口流动产生的创新溢出效应受到地理距离的约束,50~300公里是城市创新水平空间溢出效应的密集溢出区、300~500公里是边缘溢出区、500~1000公里是空间收敛区。(4)在地理距离的约束下,人口流动产生的创新溢出效应在不同城市群中存在异质性影响,京津冀、长三角与长江中游城市群能有效发挥人口流动的创新溢出效应,而珠三角与成渝城市群还未能激活人口流动的创新溢出效应。

With the deepening of negative population growth,population flow has become the key to the future compe⁃tition of urban human capital and the core driving force of urban innovation development,it is of great theoretical and practical significance to explore the impact of population mobility on urban innovation development from multiple per⁃spectives.Using the knowledge innovation and diffusion model(TP model)under the framework of spatial economics,we utilize the panel data of 283 cities in China from 2010 to 2021,combined with the method of spatial econometric modeling,and based on the dual perspectives of spatial spillovers and geographic distance constraints,we study the im⁃pact effect of population flow on the level of urban innovation.The study finds that:(1)there are obvious spatial correla⁃tion and agglomeration characteristics of urban innovation,specifically manifested as“high agglomeration”in the east⁃ern coastal area and“low agglomeration”in the inland areas such as the northeast,west and southwest.(2)The expan⁃sion of the scale of population mobility strengthens the knowledge linkage and thus significantly promotes the level of urban innovation.The decomposition of spatial effect finds that population flow has spatial spillover effect on urban in⁃novation development,and the free flow of population in space can generate knowledge spillover and diffusion effect of regional innovation development.(3)The innovation spillover effect generated by population mobility is constrained by geographic distance,50~300 kilometers is the intensive spillover zone of the spatial spillover effect of urban innova⁃tion level,300~500 kilometers is the marginal spillover zone,and 500~1000 kilometers is the spatial convergence zone.(4)Under the constraint of geographic distance,the innovation spillover effect generated by population flow has heterogeneous impacts in different urban agglomerations.The Beijing-Tianjin-Hebei,Yangtze River Delta,and the middle reaches of the Yangtze River urban agglomerations are able to effectively utilize the innovation spillover effect of population mobility,while the Pearl River Delta and the Chengdu-Chongqing urban agglomerations are not yet able to activate the innovation spillover effect of population flow.