Research On The Influence Mechanism Of Regional Integration Policy On The Spatial Pattern Of Urban Agglomerations

Promoting coordinated regional development is an important part of implementing the new development concept and an inevitable requirement for realizing high-quality economic development.As the key way and important grasp to promote regional coordinated development,regional integration is the main manifestation of city clusters and metropolitan areas in geographic space,and it is the necessary way to achieve high-quality development.The report of the 20 th Party Congress points out that we should thoroughly implement the strategy of coordinated regional development,major regional strategies,main functional area strategies and new urbanization strategies,optimize the layout of major productive forces,and build a regional economic layout and territorial spatial system with complementary advantages and high-quality development.It has made a major deployment for regional development and spatial governance in the new development stage,and pointed out the direction for promoting coordinated regional development and improving spatial governance.In fact,the number of urban agglomerations approved by the State Council has reached 11 since the first urban agglomerations were proposed in the 11 th Five-Year Plan in 2006.At present,these 11 national city clusters occupy 21% of the country’s land,gather 58% of the country’s population and create 68% of the country’s total economic output,and have become important spatial carriers to promote coordinated regional development as well as growth poles and support points to promote highquality economic development.However,the research on the economic layout and spatial system of China’s urban agglomerations is still in the preliminary exploration stage.What are the characteristics of spatial pattern such as spatial scale,spatial function and spatial form that affect the high-quality development of urban agglomerations? Is the evolution of the spatial pattern of urban agglomerations caused by the introduction of urban agglomeration development plans as a result of the implementation of regional integration policies? Are there heterogeneity and spatial effects of regional integration policies on the spatial pattern of urban agglomerations? What are the mechanisms of regional integration policies affecting the spatial patterns of urban agglomerations? All these questions need to be further studied.If regional integration policies can improve the scale structure of urban agglomerations,strengthen the functional division of labor in urban agglomerations,and enhance the network structure of urban agglomerations,thus promoting the optimization of the spatial pattern of urban agglomerations,then urban agglomeration integration will become a policy path to promote coordinated regional development and optimize the spatial pattern of the national territory.Therefore,it is of great theoretical and practical significance to study the influence mechanism of regional integration policy on the spatial pattern of urban agglomerations.Guided by the dual objectives of promoting coordinated regional development and optimizing territorial spatial pattern,this study mainly follows the logic of problem introduction → theoretical analysis → empirical analysis → policy application.Firstly,the theoretical basis and research literature on regional integration policy,urban agglomerations and spatial pattern optimization at home and abroad are reviewed and sorted out,which provides a pavement for the later discussion on the influence mechanism of regional integration policy on the spatial pattern of urban agglomerations.Secondly,the theoretical analysis framework of spatial pattern of urban agglomerations is constructed from three dimensions,including scale structure,functional division of labor,and network structure,and then the mechanisms and theoretical assumptions of the effects of regional integration policies on the scale structure,functional division of labor,and network structure of urban agglomerations are proposed respectively.Then,an empirical test is conducted on the mechanism of the influence of regional integration policies on the spatial pattern of urban agglomerations.Specifically,statistical analysis methods such as Zipf’s law,expert scoring method,data envelopment analysis(DEA),weighted average method,locational entropy,modified gravity model,social network analysis(SNA)and Moran’s index method(Moran’s I)are used,and various software such as DEAP,Ucinet,Excel,Arc Map and Stata are used to measure and explore the dynamic evolution and spatial correlation of the scale structure,functional division of labor and network structure of urban agglomerations in turn.The general effects,heterogeneity and spatial effects of regional integration policies on the scale structure,functional division of labor and network structure of urban agglomerations are examined by difference-in-differences method(DID),propensity score matching difference-in-differences method(PSM-DID)and spatial difference-in-differences method(SDID)in turn.The mediating effect model and moderating effect model are used to test the mechanisms of the role of fiscal expenditure,technological innovation,industrial structure,and digital economy in the influence of regional integration policies on the scale structure,functional division of labor,and network structure of urban agglomerations,respectively.Finally,from the regional integration policy,combining with the goal of spatial pattern optimization,the regional integration policy suggestions to promote the optimization of spatial pattern of urban agglomerations are proposed.Through the above theoretical analysis and empirical research,the main research conclusions drawn in this paper are as follows.1)The spatial pattern of urban agglomerations is a complex spatial system embedded with spatial scale,spatial function,and spatial morphological factors.There is a theoretical analysis framework consisting of three dimensions such as scale structure,functional division of labor and network structure.2)The spatial pattern of urban agglomerations in China tends to be optimized on the whole from 2006 to 2020.Among them,the scale structure of urban agglomerations is optimized in general,the specialization of functional division of labor is improved,and the centrality of network structure is gradually enhanced.3)Regional integration policies can directly promote the optimization of the spatial pattern of urban agglomerations,and there are heterogeneous and positive spatial spillover effects of regional integration policies on the spatial pattern of urban agglomerations.4)Fiscal expenditure,technological innovation,industrial structure,and digital economy are important paths through which regional integration policies affect the spatial pattern of urban agglomerations.5)To form a spatial pattern of urban agglomerations with reasonable scale,division of labor and close connection,we should start from the policy of regional integration,continuously improve the scale structure of urban agglomerations,strengthen the division of labor of urban agglomerations and enhance the network structure of urban agglomerations.The innovation of this paper is mainly reflected in the following three aspects.1)The theoretical analysis framework of the spatial pattern of urban agglomerations is constructed,and the evaluation dimensions and measurement methods of the spatial pattern of urban agglomerations are proposed,which enriches the relevant research on the spatial pattern of urban agglomerations from theoretical and empirical perspectives.2)The general impact of regional integration policies on the spatial pattern of urban agglomerations,as well as the heterogeneity and spatial effects of the impact,are discussed,expanding a new perspective on the assessment of the effects of regional integration policies.3)The mechanisms and key paths of regional integration policies affecting the spatial pattern of urban agglomerations are proposed,which provide a reference basis for decision making to promote the integrated and high-quality development of urban agglomerations.