The Impact Of Urbanization On Urban Eco-Efficiency In The Yangtze River Economic Belt

At present,China's economic development model is in a critical period of shifting from export-and investment-driven to innovation and domestic demand-driven,and the upgrading and transformation of urbanization has become an important starting point for urban modernization and sustained economic development.However,there are some conditions we must be vigilant.First,the actual national conditions of the aging population and the declining birth rate have caused the window of opportunity for the "demographic dividend" to close,and the flow of urban and rural populations is gradually slowing down.As cities are important spatial carriers of economic development,it is worth thinking about how urbanization can continue to promote the concentration of factors,expand urban domestic demand,and achieve regional economic growth.Second,the rapid development of land urbanization has caused a sharp increase in the consumption of urban energy resources and increased environmental pressure,and the sustainable development of cities is facing severe challenges.Third,the traditional thinking of urbanization distorts the factor allocation efficiency of the market mechanism,which is not conducive to the improvement of urban economic efficiency.In addition,affected by the " Corona Virus Disease 2019" epidemic,the international political and economic environment has become increasingly complex,and the transformation and development of the domestic economy is imperative,and the constraints on urban energy resources and the ecological environment have become tighter.Whether and how urbanization can play a supporting role in accelerating the agglomeration of factors,enhancing the regional economic radiation capacity,and alleviating the pressure on resources and the environment,so as to achieve the continuous improvement of urban eco-efficiency,urgently need in-depth investigation and research.At the same time,the Yangtze River Economic Belt is one of my country's major development strategies.Under the development principle of "to protect and not engage in large-scale development",it is scientific to clarify the development status,trend and time-space relationship of urbanization and regional eco-efficiency in the Yangtze River Economic Belt.Grasping the internal connection and impact mechanism between urbanization development and regional eco-efficiency has important theoretical and practical significance for exploring a green,intensive,and high-quality urbanization development path with Chinese characteristics and promoting economic stability and efficient growth.The paper firstly,on the basis of systematically combing the related theories of urbanization and eco-efficiency,profoundly explained the internal impact mechanism of urbanization construction on urban eco-efficiency,and established a more scientific and comprehensive urban eco-efficiency level evaluation index system that reflects the development strategy of the Yangtze River Economic Belt.Secondly,based on the panel data of 108 cities at prefecture level and above in the 11 provinces,autonomous regions and municipalities of the Yangtze River Economic Belt,the SBM-DEA model based on undesired output is used to measure the urban eco-efficiency.From 2007 to2018,comprehensive analysis and judgment of urban eco-efficiency were carried out,and spatial visualization technology and exploratory spatial analysis methods were used to describe and explore the differences in regional eco-efficiency levels and spatial correlations to reveal the temporal and spatial evolution of eco-efficiency in the Yangtze River Economic Belt.At the same time,based on the background of China's special system,clarify the historical evolution of urbanization in the Yangtze River Economic Belt,and use nuclear density estimation and spatial visualization techniques to investigate the dynamic evolution and temporal-spatial distribution characteristics of urbanization under different metrics.On this basis,the instrumental variable two-stage least squares method(IV-2SLS)and the instrumental variable three-stage least squares method(IV-3SLS)are used to empirically test the relationship and mechanism of the impact of urbanization on the urban eco-efficiency,and build Economic-geographic spatial weight matrix and spatial simultaneous equation model,using generalized spatial three-stage least squares method(GS3SLS)to empirically analyze the spatial spillover effect and spatial interaction of urbanization on urban eco-efficiency.And based on the above qualitative analysis and proposition testing,we propose optimized policies for urbanization to improve regional eco-efficiency.Based on theoretical interpretation and empirical research,the core point of this paper is using urbanization as a starting point to improve urban eco-efficiency in the Yangtze River Economic Belt,which has the characteristics of "path dependence".Whether it is a direct or indirect impact,the current stage is still dominated by the urbanization of traditional urban-rural floating population and spatial expansion-type land urbanization.However,the traditional urbanization model is unsustainable,and the positive impact of social urbanization and new urbanization on urban eco-efficiency needs to be further improved.At the same time,the improvement of the eco-efficiency and urbanization of surrounding cities can significantly improve the local eco-efficiency level.The specific research conclusions are as follows.(1)The urbanization of the Yangtze River Economic Belt in my country from2007 to 2018 is unevenly distributed.There is no trend of convergence at the overall level,but it shows the characteristics of "double peak" or "multi-peak" club convergence.Specifically,while the land urbanization level of the cities in the Yangtze River Economic Belt is gradually improving,its distribution has always maintained the phenomenon of convergence of multiple clubs.The population urbanization level in the Yangtze River Economic Belt has shown a high level of concentration,and the absolute gap in the level of urbanization development between cities is constantly narrowing.The level of social urbanization in the belt is slowly improving,the absolute gap between cities is gradually expanding,the low-level concentration is gradually decreasing,and the high-level agglomeration phenomenon is gradually taking shape.The development level of new-type urbanization in the belt is constantly improving,and there is polarization phenomenon,but it is still mainly manifested in a low-level agglomeration state.Based on the spatial visualization technology of Arc GIS,it is found that the spatial distribution pattern of the urbanization level of the Yangtze River Economic Belt mainly presents a typical "center-periphery" characteristic,which is specifically manifested as the core of the provincial capital or the developed coastal cities in the lower reaches of the Yangtze River.The Yangtze River Delta urban agglomerations,the urban agglomerations in the middle reaches of the Yangtze River,and the Chengdu-Chongqing urban agglomerations are the agglomeration planes,forming a “central city-urban agglomerations-economic belt” urbanization development model combining point and surface.(2)From 2007 to 2018,the level of urban eco-efficiency in the Yangtze River Economic Belt showed a fluctuating upward trend,and the overall performance was a spatial pattern of decreasing gradients in the lower,middle and upper reaches.During the period 2007-2018,there are significant differences in the average eco-efficiency of cities in the upper,middle and lower reaches of the Yangtze River Economic Belt,and there is no conditional convergence.On the whole,only the urban eco-efficiency in the middle reaches of the Yangtze River Economic Belt has been significantly improved,the downstream areas have been slightly improved,and the upstream areas have deteriorated.From 2007 to 2018,the distribution of cities with medium and above eco-efficiency in the belt gradually showed a more obvious trend of multi-club convergence.Specifically,coastal cities in the lower reaches of the Yangtze River,Wuhan urban circle,Changsha urban circle and Chengdu metropolitan circle were typical.However,the eco-efficiency of cities in Yunnan and Guizhou provinces in the upper reaches of the Yangtze River and Jiangxi Province in the middle reaches of the Yangtze River is generally significantly reduced.(3)The effect of urbanization on urban eco-efficiency is in a non-linear "U" shape,and the current effect is positive.Land urbanization,population urbanization and new-type urbanization all have a "U"-shaped non-linear relationship with urban eco-efficiency,while social urbanization has no non-linear relationship with urban eco-efficiency.It is found through calculations that land urbanization,population urbanization,and new-type urbanization have reached 3.61%,47.57%,and 9.03%,respectively,and began to positively promote the improvement of urban eco-efficiency.Taking into account in most cities at this stage,the level of land urbanization,population urbanization and new-type urbanization has basically reached or even surpassed the "U"-shaped inflection point.Therefore,urbanization at this stage has a positive and positive impact on urban eco-efficiency.Taking into account the endogenous problems of urbanization,this article chooses the sales price of urban commercial houses as the instrumental variable of urbanization.At this stage,land urbanization,population urbanization,social urbanization and new-type urbanization all have significant positive effects on urban eco-efficiency.Specifically,population urbanization has the largest impact on urban eco-efficiency,followed by land urbanization,social urbanization again,and new-type urbanization the smallest.(4)Urbanization has significantly promoted the improvement of urban eco-efficiency through the transmission mechanism of industrial structure optimization,human capital accumulation,and industrial agglomeration,but it is not conducive to the improvement of urban eco-efficiency under local government institutional competition.Population urbanization has the most obvious effect of improving urban eco-efficiency through the above three transmission mechanisms,followed by land urbanization,and social urbanization and new-type urbanization have the worst effects.At the same time,there is widespread competition among local governments.From the perspectives of land urbanization,population urbanization,social urbanization,and new-type urbanization,about 83.33%,40.28%,63.19%,and81.02% of the observations are in institutional competition.The critical value stage,that is,for most cities,under the regulation of the competition of local government institutions in urbanization,urbanization is not conducive to the improvement of urban eco-efficiency.(5)Urbanization has a significant spatial effect on urban eco-efficiency.As far as the whole area of the Yangtze River Economic Belt is concerned,the improvement of the eco-efficiency level of surrounding cities can significantly promote the improvement of local eco-efficiency,and the development of land urbanization,population urbanization,social urbanization and new-type urbanization in surrounding cities can significantly improve the local eco-efficiency level.In terms of regional differences in the belt,the direction and significance of the spatial spillover and spatial interaction between urbanization and eco-efficiency in the downstream and upstream cities are consistent with the overall estimation results of the Yangtze River Economic Belt,and the influence intensity of the downstream cities is greater.But the spatial effect between urbanization and eco-efficiency in midstream cities is relatively smaller,and most of the spatial effects have not been significantly exerted.Based on the above research conclusions,this paper reveals that the urbanization of the Yangtze River Economic Belt still has the following problems in the practice of improving urban eco-efficiency and promoting the realization of high-quality green development in the Belt.First,the development of urbanization in various regions of the Belt is uneven,and traditional population urbanization and land urbanization are still dominated at present,and the development level of social urbanization and new-type urbanization is low and the process is slow.Second,the urban eco-efficiency of the Belt presents a low level of spatial agglomeration,especially the urban eco-efficiency in the upper reaches show a significant downward trend.Third,the new-type urbanization of the Belt still has a large room for the improvement of urban eco-efficiency through the scale effect of industrial agglomeration,the accumulation effect of high-quality human capital,and the linkage development with the optimization of the industrial structure.Fourth,the horizontal blind homogenization competition between local governments represented by institutional competition is not conducive to improving the quality and efficiency of urbanization,thus hindering the improvement of the level of urban eco-efficiency.Fifth,the resource agglomeration capacity of urban agglomerations(especially the central and western urban agglomerations)needs to be further improved,and the positive spatial spillover effects and spatial interactions of urbanization on urban eco-efficiency still have much room for release.In response to the above problems,this paper proposes corresponding policy optimization suggestions from the following five aspects.First,steadily promoting the development of the new-type urbanization with "people oriented" principle to realize the transformation of urbanization construction.Second,promoting the transformation of green production and lifestyle to realize the high-level spatial agglomeration of regional eco-efficiency.Third,taking the transformation and development of urbanization as the starting point to accelerate industrial agglomeration with structural upgrades,human capital formation and accumulation,thereby enhancing urban eco-efficiency.Forth,guiding local governments to avoid vicious games,forming a benign cooperative relationship with complementary advantages and an orderly competitive market environment.Fifth,giving full play to the ability of urban agglomerations to gather resources and radiation,promote the coordinated improvement of regional eco-efficiency.The marginal contributions of this paper are mainly reflected in the following four aspects.First,this paper explains the impact path of urbanization on eco-efficiency from the perspectives of industrial structure optimization,industrial agglomeration and human capital accumulation,and innovatively designs local government institutional competition based on text analysis will be discussed to avoid falling into research silos that simply verify the existence of the environmental Kuznets curve hypothesis.Second,this paper theoretically analyzes and empirically tests the spillover effects and interactions of urbanization on urban eco-efficiency on a spatial scale,thereby providing an empirical basis for the coordinated and balanced development of eco-efficiency among the various regions of the Yangtze River Economic Belt.Third,this paper innovatively uses urban commercial housing sales prices as an instrumental variable for urbanization to ease its endogenous problems,improve the accuracy of the test results,and enhance the authenticity of the research conclusions.Fourth,relying on detailed city-level data,it highlights the development characteristics of "central city-urban agglomerations-economic belt" in China's regional integrated development strategy,which is more in line with the requirements of national regional development strategy and implementation of differentiated urbanization strategies,and the research conclusions are more scientific and reasonable.