The Influences Of High-speed Rail Network Infrastructure On The Agglomeration Economy Of Cities Along The Line

Since the opening of Beijing-Tianjin intercity high-speed rail(HSR)in August 2008,the large-scale construction of China’s high-speed rail network(HSRN)has begun.China currently has the most developed HSRN in the world.Social and economic development is deeply affected by the HSRN.In the new stage of development,China is actively implementing the regional coordinated development strategy,vigorously promoting the urban agglomeration construction,and abandoning the traditional development mode that excessively pursues the expansion of city size and economic growth.It helps to change the traditional extensive development mode and improve the level of urban agglomeration economy(UAE).On this basis,not only can the city get better development,but also can drive the development of surrounding cities,which is of great significance to promote sustainable development.It is confirmed that the key to regional coordinated development and urban agglomeration construction lies in strengthening the interconnection,division of labor and cooperation among cities.Therefore,the formation and development of UAE will break through the shackles caused by administrative boundaries.It would be influenced by the interconnection between cities in a wide geographical range.As a kind of rapid transportation infrastructure,HSRN has typical network characteristics and change the interconnection and resource allocation among the cities along the line.It also weakens the spatial barriers of the flow of production factors,which is helpful to alleviate the restrictions of urban scale on factor flow,promote the agglomeration or diffusion of economy,and form innovative activities.Thus,the HSRN is bound to have an important impact on the UAE of the cities along the line.In the face of opportunities and challenges in the new development stage,how to make good use of the HSRN to the development of different cities along the line is a vital scientific issue conducive to the realization of coordinated regional development,which urgently needs to be studied based on theory and practice.Considering the above,this study takes the network characteristics of HSRN as the cut-in point,constructs the research framework of the impact of HSRN on the AE of cities along the lines,discusses the influence of the change of interconnection between cities brought about by high-speed rail network on agglomeration economy,which enriches the theoretical understanding of agglomeration economy.On this basis,empirical analysis is carried out by using data related to China’s urban economic development and HSRN construction and operation,to quantify the degree of impact of China’s HSRN on the AE of cities along the routes,and to explore the impact characteristics,so as to provide policy basis for China’s coordinated regional economic development and HSRN infrastructure construction.In general,the main work and relevant conclusions of this study can be summarized as the following four aspects:First,through reviewing and sorting out the existing literature,the mechanism of the effect of HSRN on the AE of cities along the line is clarified.This study finds that the networked development of HSR not only not only promotes the regional allocation of economic factors through economic effects,but also strengthens the interconnection between cities along the route through network effects,and there is an interaction between economic effects and network effects.Thus,deepen the social division of labor between cities,the economic activity transaction cost saving,lead to the formation of urban network externalities,which has a great impact on the intermediate product market,labor market and knowledge spillover activities of cities along the routes.And the externality of urban network is formed.Finally,the AE of cities along the lines is improved.This study calls it the HSRN’s agglomeration economic effect(HSRNAE);Second,the complex network method is introduced into the empirical study of the economic effects of HSRN.Employing the data related to the construction and operation of HSR,this study establishes an HSRN model to reflect the interconnection between cities along the lines.On this basis,using the three key network analysis indicators,i.e.,degree,strength,betweenness,the interconnection between cities is measured.And the three indicators are weighted to obtain the index of "network position(NP)",which comprehensively reflects the interconnection between cities embedded in the HSRN.Relying on the relevant data in China from 2008 to 2018,empirical research is carried out.It can be found that the interconnection between cities embedded in the HSRN is constantly changing,and the regional imbalance is obvious.The NPs of the cities among the eastern,central and western regions are gradually decreasing,the gap between the north and the south is widening,the gap between the core cities and peripheral cities is widening,and the gap between the regions along the trunk lines and the branch lines is widening;Third,the HSRNAE is empirically tested by using panel data analysis model,mediating effect model and grouping regression analysis.It can be found that the HSRN has a significant positive impact on the AE of the cities along the lines,but this impact has regional disparity.Firstly,for a city with a better economic foundation,the promotion effect of HSR on AE is usually better.This conclusion is reflected in the comparative analysis between core cities and peripheral cities,as well as among the eastern,central and western regions.Secondly,the larger the urban population is,the stronger the HSRNAE will be,and vice versa.However,when the urban population size is less than500,000,the HSRNAE is no longer significant.Finally,the heterogeneity analysis results from the perspective of urban spatial location show that the HSRNAE is greater for cities with the "commuting distance from the nearest core city" within 100-200 km than for cities within 100 km and more than 200 km,respectively,which verifies the "agglomeration shadow" hypothesis.In addition,the robustness test based on the replacement of the core explained variables and the construction of instrumental variables based on geographic environmental information and the use of two-stage least square estimation shows that the conclusion that "HSRN promotes the economic development of AE along the lines" is robust;Fourthly,based on the research of two orientations,the paper empirically tests the influence mechanism of HSRN on AE of cities along the lines.Among them,the mechanism-oriented research shows that the HSRNAE can improve the housing cost affordability of urban residents,which helps to promote the agglomeration of population to the cities along the line and finally promote the development of AE.According to the counterfactual oriented research,it can be found that although some cities can enjoy the dividends brought by the construction and operation of HSRN,economic development potential of some other cities is sacrificed;Based on the above,this study believes that the construction of HSRN,the integration of HSR trunk line and branch line,and the coordination of HSRN and other means of transportation infrastructure should be vigorously promoted,so as to provide conditions for the cross-regional flow of economic factors.Besides this,it needs to make efforts to remove barriers to the circulation of economic factors between cities,which helps to optimize the spatial structure of urban system and promote regional coordinated development.The possible innovation of this article is reflected in the following three aspects:(1)Combining the research on AE with the research on the network characteristics of HSR,reconstructing the key factors in the theoretical system of urban AE development,enriching the theoretical understanding of agglomeration economy;(2)Establishing the HSRN model based on the train information by employing the network analysis method,and comprehensively and objectively describing the network position(NP)of the cities along the HSR based on the degree,strength and betweenness,highlighting the differences in the HSRN operation capacity between different cities,so as to make the evaluation result of the HSR economic effect more accurate;(3)When using the econometric model to evaluate the impact of HSRN infrastructure on the AE of cities along the line,this article examines the possible differences between urban endowment and location factors from multiple levels and angles,which not only makes the research conclusions more comprehensive,but also makes the conclusions more valuable for policy guidance.