Under the background that China’s economic development has changed from high-speed growth stage to high-quality development stage,the adjustment of urban-rural structure of population has been changing constantly.The problem of how the agglomeration of urban population promotes the steady development of labor productivity is worth paying attention to.In the process of economic development,the city has matched the perfect infrastructure to attract the population to gather to the city,and the labor factor brought by the population agglomeration will in turn further promote the improvement of urban economic efficiency.Domestic and foreign studies have proved that population agglomeration produces spillover effects through skills learning,knowledge sharing,information dissemination and other channels to form agglomeration economy.From the theoretical point of view,population agglomeration promotes the improvement of urban labor productivity through the economic effect of agglomeration.However,in reality,the excessive agglomeration of urban population increases the construction cost of the city,brings traffic congestion,environmental pollution,the increase of the cost of living and production,and so on,which hinders the improvement of social and economic efficiency.Therefore,this paper will study the relationship between population agglomeration and regional labor productivity,and propose that population agglomeration plays an important role in labor productivity from two aspects:positive externality and negative externality.On the other hand,the explanation mechanism of traditional research on how the positive externality of population agglomeration can promote the improvement of labor productivity is not sufficient.Therefore,this paper deeply explores that population agglomeration promotes labor productivity through labor pool effect and human capital externality effect.Based on the analysis of the theory and the analysis of the literature,firstly,through the analysis of the relationship between population agglomeration(JJD index)and urban labor productivity in national and subregional samples,this paper puts forward that population agglomeration affects urban labor productivity through the positive externality and negative externality of agglomeration,and focus on the analysis of population agglomeration mainly through the labor pool effect and human capital externality effect play a positive externality role.Secondly,according to the mechanism analysis,this paper tests the relationship between population agglomeration and labor market and human capital,and clarifies the promoting effect of population agglomeration on labor productivity through these two paths.Then,through system GMM estimation based on the dynamic panel data of 272 prefecture-level cities in China from 2006 to 2016,the paper deeply analyzes the regional heterogeneity and establish a multiple intermediary effect model to test the intermediary transmission mechanism of labor market pool and human capital externality to labor productivity.It is found that there is an inverted"U"relationship between population agglomeration and regional labor productivity in China,but there are regional differences between the two.Because of the late economic development in the western region,the supporting facilities in the region are not sound enough.On the left side of the reverse"U" type,the population concentration can greatly promote the improvement of the labor productivity through the sharing effect of the labor market and the externality effect of the human capital.Finally,according to the mechanism and empirical analysis of this paper,combined with the urban development planning of our country,the relevant countermeasures and suggestions are given. |