| Under the background of deepening economic adjustment of the world,nowadays,the construction of transportation infrastructure is increasingly becoming a driving force to promote economic growth,and the demand for domestic and foreign transportation is growing "explosively".For the " the Belt and Road " strategy and the three major strategies,we must carry out the demand for large transport infrastructure links,demand for transportation infrastructure construction with new urbanization and new rural construction,demand for railway speed raising and vigorously developing high-speed rail industry,and the demand for transportation infrastructure to communicate with all countries along the " the Belt and Road ".It is of great practical significance to deepen the construction of transportation infrastructure step by step.On the one hand,the traditional research on transport infrastructure,most scholars often do not take into account the spatial correlation of transport infrastructure,and only a small number of scholars study the non-linear relationship between transport infrastructure and industrial agglomeration and the non-linear relationship between industrial agglomeration and traffic economic effect,and only a small number of scholars’ study from the perspective of threshold effect.On the other hand,most scholars believe that industrial agglomeration has only intermediary effect on the economic growth effect of transport infrastructure,and often neglects the regulatory effect,interaction effect and threshold effect of industrial agglomeration.Therefore,from the practical and theoretical point of view,it is necessary to conduct in-depth research on transport infrastructure and the relationship between transport,industrial agglomeration and economic growth,so as to provide theoretical and empirical support for formulating specific transport infrastructure construction policies.Therefore,this paper mainly focuses on testing and empirical analyzing the spatial spillover and threshold effect of transport infrastructure and the organic interaction among transport infrastructure,industrial agglomeration and economic growth.The main research focuses on the spatial spillover and threshold effects of transport infrastructure,and then divides them into three sub-problems: first,the impact of transport infrastructure on industrial agglomeration and spatial spillover effects and threshold effects;second,the impact of transport infrastructure on economic growth and spatial spillover effects;third,the effect existence of industrial agglomeration in the impact of transport infrastructure on economic growth.Therefore,following the problem orientation,the research ideas of this paper are as follows: under the theoretical framework of traditional economics and new economic geography,firstly,this paper theoretically analyses the relationship among transport infrastructure,industrial agglomeration and economic growth;secondly,from the perspective of time series empirical research,it studies the short-term and long-term dynamic relationship between transport infrastructure and economic growth.Thirdly,from the perspective of panel data,the paper analyses the spatial spillover effect and threshold effect of comprehensive transportation and highway transportation on industrial agglomeration and economic growth in three big city groups of China,and then makes empirical analysis on the adjustment effect,interaction effect,intermediary effect and threshold effect of industrial agglomeration in the impact of transport infrastructure on economic growth,and finally draws the main conclusions and policy recommendations.There are eight chapters in this paper.Firstly,the theoretical basis is sorted out.Then,according to the combination of theoretical analysis and empirical analysis,the spillover effect of transport infrastructure and its interaction mechanism are theoretically analyzed.the main body of the three chapters is empirical study.The spillover effect and threshold effect of transport infrastructure on industrial agglomeration,The spillover and threshold effects of transport infrastructure on industrial agglomeration,spillover and threshold effects of transport infrastructure on economic growth,and the‖ existence effect‖ and threshold effects of industrial agglomeration on economic growth effects of transport infrastructure.Finally,providing some conclusions and policy recommendations.According to this idea,it can be divided into three parts:The first part is a review of literature and basic theories,mainly involving the contents of Chapter 1 and Chapter 2.Chapter 1 is an introduction,which mainly talks about the background,main contents and innovations.Chapter 2 is a literature review and theoretical combing.It describes the theoretical knowledge involved in this paper,and combs the previous studies,identifies the advantages and disadvantages,and carries out research aiming at the shortcomings.The second part is the main part of the combination of theory and practice.Including Chapter 3 to Chapter 7.Chapter 3 gives a general overview of the spillover mechanism of transport infrastructure and the mechanism of the relationship among transport infrastructure,industrial agglomeration and economic growth.This paper theoretically discusses the impact mechanism of transportation infrastructure on industrial agglomeration,the impact mechanism of transportation infrastructure on economic growth and the utility transmission mechanism of industrial agglomeration in the impact of transportation infrastructure on economic growth.Based on theoretical analysis,it not only theoretically analyses the possible intermediary effect of industrial agglomeration,but also regulates the possible effect of industrial agglomeration.The mechanism of interaction effect and threshold effect was analyzed.Chapter 4 empirically studies the dynamic relationship between transport infrastructure and economic growth.Using the time series data from 1978 to 2017,this chapter conducts unit root test,Granger causality test,cointegration test,VAR vector autoregressive model regression,impulse response and variance decomposition analysis,and finds out the relationship of the transport infrastructure and economic growth has a linkage effect,and they have a stable dynamic relationship in the short and long term.Chapter 5,using national panel data,constructs general panel model,spatial econometric model and panel threshold model,examines and empirically studies the relationship,spatial spillover effect and threshold effect between comprehensive transport infrastructure,highway transport infrastructure and industrial agglomeration.From the national point of view,comprehensive transport infrastructure has a significant non-linear impact on industrial agglomeration,showing a "inverted U" non-linear relationship,and transport infrastructure has a significant negative spatial spillover effect.However,the regression coefficient and spatial spillover effect of highway transport infrastructure are significantly positive.The positive and negative spatial spillover effects of comprehensive traffic and highway traffic are significantly different.From the point of view of the three big city agglomerations,the comprehensive transportation infrastructure in the Yangtze River Delta has a significant negative impact on industrial agglomeration,while highway has a significant promoting effect on industrial agglomeration;the comprehensive transportation infrastructure in the middle reaches of the Yangtze River has no significant impact on industrial agglomeration,and the highway transportation infrastructure has a "U-shaped" non-linear impact on industrial agglomeration.― The comprehensive transportation infrastructure of Diamond Economic Circle has a non-linear effect on industrial agglomeration,showing an inverted U-shaped non-linear relationship,which is similar to the overall regression results of the whole country.Highway transportation infrastructure has a significant negative impact on industrial agglomeration.As a threshold variable,the comprehensive transport infrastructure of the whole country has a single threshold,and on both sides of the threshold,the transport infrastructure has a significant negative impact on industrial agglomeration.Chapter 6 explores the spatial spillover effects of comprehensive transport infrastructure and highway transport infrastructure on economic growth from the national level and the regional level of the three metropolitan agglomerations.At the national level,using the panel data of 273 prefecture-level cities in China from 2001 to 2015,using the means of general panel model and spatial econometric model respectively,from the perspective of comprehensive transport infrastructure and highway transport infrastructure,the impact of transport infrastructure on economic growth and spatial spillover effect are analyzed,and their relationship and spatial spillover effect are explored.From the national point of view,comprehensive transport infrastructure has significant positive impact on economic growth,significant spatial spillover effect,significant direct effect,indirect effect and total effect.Highway transport infrastructure has significant positive impact on regional economic growth,but highway has no significant spatial spillover effect on economic growth in adjacent areas.At the regional level,the impacts of transportation infrastructure on economic growth and spatial spillover effects of the Yangtze River Delta urban agglomeration,the middle reaches of the Yangtze River urban agglomeration and the "diamond economic circle" are explored from the aspects of comprehensive transportation and highway transportation.The comprehensive transportation infrastructure of the Yangtze River Delta urban agglomeration has significant spatial spillover effect;the transportation infrastructure of the middle reaches of the Yangtze River urban agglomeration has a significant positive effect on economic growth,and has a significant spatial spillover effect on adjacent areas;the impact of the transportation infrastructure of the "diamond economic circle" and economic growth has a non-linear relationship and has significant spatial spillover effect.Chapter 7,from the national level and the three metropolitan agglomerations level,explores the impact effect of industrial agglomeration on the relationship of economic growth with comprehensive transport infrastructure and the relationship of economic growth with highway transport infrastructure.The effect is regulatory effect,interaction effect or intermediary effect? Is the regulatory effect non-linear? The threshold effect of industrial agglomeration on the relationship of economic growth with comprehensive transport infrastructure and with highway transport infrastructure is analyzed in depth.As far as the whole country is concerned,industrial agglomeration has no significant regulatory effect on the economic growth effect of comprehensive transportation.Industrial agglomeration has significant non-linear regression regulatory effect and interaction effect on the relationship between highway transportation infrastructure and economic growth.Industrial agglomeration has no significant regulatory effect on the relationship between highway transportation and economic growth,but has significant negative intermediary effect on relationship between comprehensive transportation and economic growth.As far as the three big city circles are concerned,the industrial agglomeration of the Yangtze River Delta city agglomeration has no intermediary effect on the comprehensive transportation infrastructure,but has a significant positive regulatory effect.The industrial agglomeration of the Yangtze River Delta city agglomeration has no intermediary effect on the highway transportation,but has a non-linear regressive regulatory effect,and the effect is decreasing firstly and then increasing;the industrial agglomeration of the middle reaches of the Yangtze River urban agglomeration has no intermediary effect and regulatory effect on the comprehensive transportation,industrial agglomeration has no intermediary effect on highway transport infrastructure,but has significant U-shaped non-linear regression regulation effect,which decreases first and then increases;Diamond Economic Circle industrial agglomeration has no intermediary effect on comprehensive transport infrastructure,but has significant inverted U-shaped non-linear regression regulation effect which increases first and decreases later,and industrial agglomeration has no regulatory effect,interaction effect or intermediary effect on highway transport infrastructure.Industrial agglomeration has a single threshold value for comprehensive transportation infrastructure.When industrial agglomeration is less than or equal to the threshold value and greater than the threshold value,transportation infrastructure has a significant role in promoting economic growth.Industrial agglomeration also has a single threshold value for highway transportation infrastructure.Highway transportation infrastructure has no significant effect on economic growth when industrial agglomeration is less than or equal to the threshold value.When industrial agglomeration is greater than the threshold value,highway traffic has a significant effect in promoting economic growth.The last part is Chapter 8,which summarizes the full text,policy recommendations and research prospects.Chapter 8 is the summary of the whole paper.Mainly make a general summary of the previous research in each chapter,put forward the corresponding policy recommendations for the conclusions of the summary,and in view of the deficiencies of this study,put forward the direction of future research.After in-depth thinking and summary,the author believes that there are four possible innovations in this paper:First,it enriches the theoretical discussion on the relationship between transportation infrastructure,industrial agglomeration and economic growth from different perspectives.From the perspective of new economic growth theory and transportation cost from the perspective of new economic geography,this paper explores the theoretical mechanism of traffic affecting economic growth and industrial agglomeration;enriches the theoretical and empirical research on the relationship between them from the perspective of regulation effect and interaction effect;secondly,it makes a horizontal comparative study on the traffic of the whole country,the Yangtze River Delta urban agglomeration,the middle reaches of the Yangtze River urban agglomeration and the "diamond economic circle".Infrastructure impacts on spatial spillover effects of industrial agglomeration differentiation,non-linear threshold effects and spatial spillover effects of traffic on economic growth is different,and further compares the different effects of industrial agglomeration on the relationship between transport infrastructure and economic growth.Thirdly,it enriches the content of New Economic Geography about the impact of transportation cost on industrial agglomeration.Empirical research reveals that transportation infrastructure has a non-linear impact on industrial agglomeration and industrial agglomeration on the economic growth effect of transportation infrastructure,and explores the existence of threshold effect.Fourthly,the detailed data of 273 prefecture-level cities in China are used.Generally speaking,most scholars use provincial-level data,while fewer scholars use prefecture-level data.Using various empirical research methods,this paper empirically studies the spatial spillover,threshold effect and the effect of industrial agglomeration on the relationship between transport and economic growth,and explores some new and comparable empirical conclusions. |
