Study On The Influence Of Population Agglomeration On Labor Productivity In Chengdu-chongqing Twin Cities Economic Circle

This paper takes the impact of population agglomeration on labor productivity as the research objective.Firstly,the JJD index is used to calculate the population agglomeration degree,and the formula of GDP per labor is used to calculate the three labor productivity.According to the results,the population agglomeration level and the current situation of labor productivity are analyzed.Secondly,the Threshold Model is used to estimate the impact trend of population agglomeration on labor productivity.Finally,we add two mediating variables,labor stock and human capital stock,and use the Mediating Effect Model to test whether these two mediating variables play a conduction role in the process of population agglomeration affecting labor productivity.Through the analysis of the above steps,the following conclusions are drawn:（1）Population agglomeration and labor productivity: 1)Population agglomeration: Generally speaking,Chengdu has the highest population agglomeration level,while Guangyuan has the lowest;The population concentration level of the prefecture-level cities around Chengdu and Chongqing shows a decreasing trend from Chengdu and Chongqing to the surrounding areas.2)Labor productivity: Guang ’an has the highest labor productivity in the secondary industry,while Bazhong has the lowest;Chengdu has the highest labor productivity in the tertiary industry,while Bazhong has the lowest.Chengdu,Chongqing,Meishan,Zigong,Leshan,Guang ’an,Ziyang,Neijiang and so on have higher overall labor productivity level,while Bazhong has the lowest labor productivity level in the second and third industries.The three labor productivity areas show the same law: the number of low labor productivity areas decreases year by year,the number of middle labor productivity areas increases first and then decreases,and the number of high labor productivity areas increases year by year（2）Results of Threshold Model: The empirical study adopts double threshold model.The labor productivity of the secondary industry decreases with the increase of population concentration,which is in the right half of the inverted "U" shape.The productivity of the tertiary industry increases with the increase of population concentration,which is in the left half of the inverted "U" shape.With the increase of population agglomeration degree,the overall labor productivity will decrease,then rise and finally decline again,but only the influence on the rising stage is significant.（3）Test of Mediating Effect Model: population agglomeration has significant mediating effect on secondary industry,tertiary industry and overall labor productivity through labor stock and human capital stock.