Dissertation Title(Times New Roman,Bold,Centered,Multi-lines Allowed)

Since the 19 th National Congress of the Communist Party of China,high-quality development has become the main theme of China’s development,and the 20 th National Congress of the Communist Party of China has elevated the realization of high-quality development to the height of "the primary task of comprehensively building a socialist modern country.".The economic development of urban agglomerations in the Yangtze River Delta is active,and it is regarded as an important engine for China’s economic development.However,due to factors such as geographical conditions and economic policies,there are significant differences in high-quality economic development.Moderate differences are conducive to giving full play to regional comparative advantages and promoting economic efficiency.However,large differences in economic development between regions can have a negative impact on economic efficiency.At the stage of high-quality development,how to narrow regional economic development differences,achieve integrated and coordinated development,and build the Yangtze River Delta urban agglomeration into a worldclass urban agglomeration is a hot issue in current research.In view of the current situation of economic development in the Yangtze River Delta urban agglomeration,this article uses economic statistical methods to analyze the spatiotemporal evolution,influencing factors,and the coordinated development degree of various cities of the economic development differences in the Yangtze River Delta urban agglomeration.Firstly,relevant theories and research are reviewed and summarized,and the connotation of high-quality development and coordinated development is elaborated.Secondly,a multiple indicator comprehensive evaluation method is used to measure the high-quality economic development index,revealing the current situation of high-quality economic development in the Yangtze River Delta urban agglomeration.Then,spatial analysis method is used to analyze the spatiotemporal evolution characteristics of economic development differences,and geographical detector models are used to detect the impact factors of economic development differences,Finally,based on the research results,suggestions are proposed to promote the high-quality and coordinated development of the Yangtze River Delta urban agglomeration economy.The research results show that the high-quality economic development of the Yangtze River Delta urban agglomeration has achieved stable growth,and the strong economic radiation effect of developed cities has led to high growth in some low-level cities.However,there are still significant differences in their internal economic development,mainly from among provinces,with the largest differences within Anhui Province,followed by Zhejiang and Jiangsu Province.Therefore,the gap in the economic development of the Yangtze River Delta urban agglomeration has been narrowed The primary task of promoting coordinated regional development is to narrow the differences between provinces.From the perspective of spatial layout,the economy of urban agglomerations in the Yangtze River Delta exhibits a distribution pattern of "strong in the east and weak in the west".The economic development of urban agglomerations has a certain degree of positive correlation in space,and there is a phenomenon of spatial agglomeration;The proportion of cities in developed regions has increased,while the proportion of cities in backward regions has decreased.The overall development level of the region has increased.Driven by developed cities,economic development has a trend of convergence.Among the eight factors that may have an impact on economic development differences,industrial structure,material capital,human capital level,labor input,and urbanization level have a significant impact.At the same time,it is found that the interaction of factors is a dual factor enhancement or non-linear enhancement.Finally,based on empirical analysis,some suggestions are proposed to narrow the urban economic gap and promote coordinated regional development,with a view to providing reference for the coordinated economic development of the Yangtze River Delta urban agglomeration.