Study On The Impact Of High-speed Rail Opening On The Optimization Of Industrial Structure In The Yangtze River Delta Urban Agglomerationa

"High-quality development" is reflected in the industrial structure,including the transformation,optimization and upgrading of industrial structure.The industrial structure optimization is an important part of the economic development,but in the economic development of our country,the high speed railway plays an extremely important role.High-speed railway promotes the flow of production factors between cities,promotes the development of regional economy and influences the change of urban industrial structure.The 14 th Five-Year Plan and the Outline of the 2035 Vision Goals and the Medium-and Long-Term Railway Network Plan 2016-2025 specify that the "eight vertical and eight horizontal" high-speed railway network will be basically integrated,and a high-speed railway network connecting major city clusters and basically connecting provincial capitals with other large and medium-sized cities will be built one after another.Since the opening of the first high-speed rail line in 2008,China has fully completed its "four vertical and four horizontal" high-speed rail network.The integration of the Yangtze River Delta urban agglomeration has been a national strategy for nearly four years.Promoting the Yangtze River Delta urban agglomeration’s development have great significance for leading the country’s high-quality development and building a modern economic system.Therefore,it is also of great significance to explore the impact of the opening of high-speed rail on the optimization of industrial structure in the Yangtze River Delta urban agglomeration.Based on the background of the rapid development of high-speed rail,this paper takes the industrial structure of the Yangtze River Delta city cluster as the research object,and analyzes the impact of high-speed rail on the optimization of the industrial structure of the Yangtze River Delta city cluster from both theoretical and empirical aspects.On the basis of researching and combing domestic and foreign literature,using theories related to industrial layout,transportation economy,regional coordinated development and analyzing the influence mechanism of high-speed rail on industrial structure optimization,the current situation is analyzed,the data analysis is used to analyze the development overview of high-speed railway in the Yangtze River Delta,the status quo of industrial structure optimization,and an index system is constructed to measure the level of industrial structure optimization.Empirical analysis mainly includes the selection of research indicators such as industrial structure optimization and high-speed rail opening,sample selection of Yangtze River Delta urban agglomeration,data sources and model introduction and setting of various variables.The fixed-effect model of DID double difference was used for research,and robustness tests were carried out by various methods such as parallel trend and placebo test.This paper draws the following conclusions: First,the opening of high-speed rail has a positive effect on the optimization of industrial structure in the Yangtze River Delta urban agglomeration,among which the opening of high-speed rail has a more significant effect on the upgrading of industrial structure;Second,the impact of the opening of high-speed rail on the optimization of industrial structure has time lag;Third,the impact of the opening of high-speed rail on the optimization of industrial structure has the heterogeneity of the length of growth cycle and the heterogeneity of urban development scale.Based on this,suggestions are made from the perspectives of formulating differentiated industrial development policies according to local conditions,rationally allocating high-speed rail economic resources,rationalizing the high-speed rail economic evaluation system,giving play to the urban linkage effect,increasing R&D funding,and promoting urbanization development and expanding employment.