The Impact Of Metropolitan Area Spatial Structure On Economic Performance: Theoretical And Empirical Researc

With the continuous advancement of urbanization in China,the development of big cities is increasingly characterized by metropolitan regionalization.On the one hand,the population and industry continue to concentrate in big cities and their surrounding areas,which has become a continuous trend in space;on the other hand,the continuous improvement of transportation infrastructure makes the long-distance and even cross administrative border commuting become an increasingly common phenomenon.At the same time,the congestion effect of big cities has been widely concerned by the academic and political circles.Drawing on the experience of developed countries,there are more and more policies and practices to promote the multi center development of metropolitan areas and metropolis circles aiming at alleviating the congestion of large cities and improving economic performance.Theoretically,metropolitan area and metropolis circle are two different forms of urbanization space,and their polycentric development policies have different goals and paths,and their effects may also be different.But in reality,the use of the concepts of city,metropolitan area,metropolis circle and urban agglomeration is still in a relatively chaotic situation.The research in the field of regional spatial structure believes that the economic performance of multi center depends on the spatial scale and the stage of urbanization development.It is of great theoretical and practical significance to scientifically understand and define the metropolitan area,and study the relationship between its multi center development and economic performance,so as to guide the choice of urbanization development path and improve the comprehensive carrying capacity of the central city.In this paper,the study of metropolitan spatial structure is divided into five parts:concept study,theoretical research,fact research,empirical research and mechanism research,and concept research is the premise of all the work..Based on the concept research,we believe that metropolitan area is a big city in the sense of economics,a unified labor market area formed around the main employment centers of big cities,and commuting is an important representation of it.China’s cities are not cities in the sense of economics,but the basic administrative units for the government to provide public services and coordinate social governance.According to the administrative sense of city allocation of resources,it is inevitable that there are various problems such as market segmentation and vicious competition.To solve these problems,we need to coordinate various systems and policy arrangements.The urbanization spatial form of metropolis circles and urban agglomeration has become an important space carrier to promote the regional integrated development,and the spatial scope is dominated by the government.In theory,metropolis circle is the regional combination within the radiation scope of big cities,while urban agglomeration is composed of different metropolitan areas in space.However,in the context of China’s urbanization,the theoretical metropolis circle and urban agglomeration may not be mature in reality.These concepts tend to be a place-based policy,which aims to reduce the degree of market segmentation and maximize the agglomeration externality between cities.The big difference lies in the spatial form.The spatial scale of urban agglomerations is too large,and the cost of inter city coordination is high.It has more operational advantages to promote the regional coordinated development around the construction of small-scale,cross regional and precise metropolis circles.As the metropolitan area is a unified labor market,the implementation of polycentric development strategy in this spatial scale can not only alleviate the crowding effect,but also not lose the scale economy of agglomeration.In theoretical research,this study absorbs the existing literature on the theory of monocentric and polycentric,and constructs a theoretical analysis framework of the impact of metropolitan spatial structure on economic performance.In the mathematical model,the Au and Henderson(2006)optimal city size model is extended from a single center city to a multi center metropolitan area combined with Alonso’s(1973)theory of “borrowing size”.According to the idea of structure-behavior-performance(SCP),the mechanism of polycentric development affecting economic performance in metropolitan area is analyzed.The results of theoretical research show that when the population scale of metropolitan areas is expanding and the supply of commuting infrastructure is relatively insufficient,if there are multiple employment centers in metropolitan areas,workers can choose to work nearby,reduce the effective labor loss caused by excessive commuting,and improve productivity.In particular,when the crowding effect of a single center is dominant,and multiple centers can borrow scale from each other,or there is agglomeration externality spillover among multiple centers,the advantage of polycentric development in metropolitan area will be greater.From a practical point of view,the spatial distribution characteristics of public services and the supply of commuting infrastructure in China determine that metropolitan areas are more likely to produce crowding effect.Therefore,we propose a theoretical hypothesis that polycentric development in metropolitan areas can reduce the crowding effect caused by over concentration of population and employment,and improve economic efficiency.In fact research,this paper uses Land Scan population grid data,night light data and Baidu API route planning technology to define the space of 37 major metropolitan areas in China.The results show that,except Chongqing metropolitan area and Dalian metropolitan area,other metropolitan areas all span the administrative boundary.Among the metropolitan areas that cross the administrative boundary,only three metropolitan areas completely cover the administrative area of the big city.In all 37 metropolitan areas,15 metropolitan areas are partially overlapped with other metropolitan areas.It should be noted that the metropolitan areas defined in this paper are potential metropolitan areas,which have the conditions of commuting infrastructure to form a unified labor market.The peripheral commuting rate of potential metropolitan areas is not high,which may be caused by various institutional constraints such as the inadequate supply of peripheral public services and construction land,and discrimination in registered residence.It is the imbalance of spatial structure on this scale that aggravates the crowding of big cities in China.Using the spatial structure measurement method,we find that 18 out of 37 major metropolitan areas in China have shown a trend of multi center development.However,the trend of polycentric development in Shanghai metropolitan area,Shenzhen metropolitan area,Guangzhou metropolitan area and Hangzhou metropolitan area still exists.In empirical research,this paper uses the 2001-2014 China industrial enterprise database to explore the economic performance of metropolitan spatial structure from the perspective of micro enterprise productivity.The results show that the polycentric development of metropolitan area is more conducive to the improvement of enterprise productivity.After changing the explained variables and explanatory variables,adjusting the regression samples,using a series of supplementary tests such as time phased regression and instrumental variable regression,the conclusion is still robust.Considering the heterogeneity of population density in metropolitan areas,the greater the population density,the greater the productivity gain in the process of polycentric development.The higher the population density is,the more obvious the crowding effect is,and the greater the advantage of polycentric development is.Considering the traffic heterogeneity of the metropolitan area,the metropolitan area without Metro can gain more enterprise productivity gain in the process of multi center development.In theory,subway,a convenient transportation infrastructure,can reduce the effective labor loss under long-distance commuting,thus increasing the feasibility of employment concentration in metropolitan areas.Considering the center periphery heterogeneity,polycentric development can significantly improve the productivity of both the central and peripheral enterprises in metropolitan areas,but relatively speaking,the peripheral enterprises gain more productivity in the process of polycentric development.This conclusion means that the construction of multi center metropolitan area is an important way to give consideration to regional high-quality development and coordinated development.In mechanism research,this paper uses the data of central city housing price,congestion and environmental pollution to empirically explore the role of polycentric development in avoiding and reducing congestion effect.On the one hand,traffic congestion,high house prices and increasing pollution are the direct embodiment of the degree of congestion;on the other hand,these congestion characteristics are usually not conducive to the improvement of enterprise productivity.Based on the congestion delay index released by Gaud map,we find that the more congested the central city is,the more productivity gains the polycentric development of the metropolitan area will bring,which indicates that the polycentric development of the metropolitan area can avoid the negative impact caused by the congestion of the central city.Based on the data of housing prices in central cities,we find that polycentric development in metropolitan areas can not directly reduce the housing prices in central cities,but enterprises still gain productivity gains in the process of multi center development,which indicates that peripheral enterprises avoid the negative impact of high housing prices in central cities.Based on PM2.5 grid data,we find that the polycentric development of metropolitan area can not only reduce the pollution level of central cities,but also avoid the negative impact of high pollution of central cities in the process of polycentric development.This study can provide a new perspective for the adjustment of spatial structure to improve the capacity of comprehensive carrying capacity and optimal allocation of resources of China’s central cities,and also enrich the relevant research on the spatial structure of metropolitan areas and regions.Specifically,first,it answers the question of “what” is the spatial form of urbanization of metropolitan areas.At present,the concepts of city,metropolitan area,metropolitan area and urban agglomeration are not clearly defined by the academic circles and the government,and misused and mixed use are common.Based on the theory of urban and regional economics and the reality of China’s urbanization,this study accurately defines the concepts of Chinese city,metropolitan area,metropolitan area and urban agglomeration,and analyzes the relationship and difference between the concepts.Furthermore,we extract the potential commuting areas of big cities from multi-dimensional big data,define the spatial structure of 37 major metropolitan areas in China,and study the evolution characteristics of the spatial structure of each metropolitan area.Second,it answers the question of “why” in the evolution of metropolitan spatial structure.Previous studies have found and pointed out the advantages of polycentric development in China’s big cities,but the research objects mainly focus on the administrative cities,and lack of theoretical and empirical research on the spatial structure of metropolitan areas.In this paper,the spatial structure factor is introduced into the urban economic model,and the relationship between polycentric development and economic performance in metropolitan areas is discussed theoretically,and the empirical evidence from the micro enterprise level is provided.Third,it answers the question of“how” to adjust the spatial structure of metropolitan areas.The development of multi center and suburbanization is an important direction of the spatial structure adjustment of big cities in China in the future.According to the framework of “six in one” of function,industry,population,transportation,public service and ecology,we can promote the construction of multi center metropolitan area,relieve the pressure of resource bearing in the central area of big cities,and promote regional coordinated development.