Internal Economic Connection,spatial Network Structure And Green Economic Efficiency Of Urban Agglomeration

Since the industrial revolution,human production and living activities have brought heavy pressure on resources and environment,and the contradiction between economic development and environmental protection has been deepening.Changing the mode of economic growth has become the primary measure to solve the above contradiction.The notion of green development is in the same line as the sustainable development.It carries out economic activities based on the status of ecological environment and resource stock.Xi Jinping’s concept of green development shows that China attaches importance to green development and also global ecological problems.At present,China’s economic development focuses on promoting the development strategy of regional economic integration.Urban agglomeration is a typical representative of the development of regional economic integration.Urban agglomeration realizes economic benefits and promotes regional economic development through multiple effects.The transformation of economic development mode of urban agglomeration is of great significance to the high-quality development of China’s economy.The Yangtze River Delta urban agglomeration is a world-class urban agglomeration with developed economy and sophisticated development.In the overall situation of China’s national modernization and opening-up pattern,the Yangtze River Delta urban agglomeration is playing a crucial role in national modernization and opening-up,but the environmental problems have become the bottleneck.Changing the economic growth mode of the Yangtze River Delta and realizing green development is of great significance to leading the country’s high-quality development and building a modern economic system.This paper takes the Yangtze River Delta Urban Agglomeration as the research object,calculates the inter city economic connection matrix through the modified gravity model,and analyzes the spatial structure characteristics of the internal economic connection network of the Yangtze River Delta Urban Agglomeration by using the social network analysis method.It is found that the internal economic connection of the Yangtze River Delta urban agglomeration is becoming closer and closer,all cities in the region are gradually integrated into the network system,the number of network connections is increasing,and the overall network density is increasing year by year,The internal economic connection network of the Yangtze River Delta urban agglomeration has been gradually improved,but the imbalance of economic connection in the Yangtze River Delta urban agglomeration always exists;In addition,through the aggregation subgroup analysis,the threelevel subgroups formed in the Yangtze River Delta urban agglomeration are mainly distributed around the economic development belt and urban development circle.Secondly,the super SBM model is used to calculate the green economic efficiency of 26 cities in the region from 2005 to 2018.Overall,the green economic efficiency of the urban agglomeration in the Yangtze River Delta is relatively high,but its green development level still needs to be improved,and the green development level of various regions in the region varies greatly.Finally,the Tobit model is used to study on the impact of the strength of economic ties and the characteristics of spatial network structure on the efficiency of green development.The conclusions are as follows:(1)the impact of economic ties between cities on green economic efficiency is significantly positive,but the degree of economic ties within urban agglomerations plays a different role in promoting green economic efficiency in different regions.The impact of urban economic ties between cities with similar development level on green economic efficiency is greater.(2)The impact direction of point out degree on green economic efficiency is related to other conditions.When economic level,urbanization degree,foreign trade and other factors are not considered,the impact of point out degree on green economic efficiency is negative.When control variables are added,the positive impact of point out degree on green economic efficiency increases;The impact of penetration on the efficiency of green economy is significantly negative.(3)In terms of foreign trade,the proportion of the actual amount of foreign direct investment in GDP has a significant negative impact on the efficiency of green economy;From the empirical results,it is proved that there is a "pollution paradise" hypothesis in the Yangtze River Delta urban agglomeration,and foreign investment has caused harm to the local environment.(4)The level of urbanization and the amount of scientific expenditures have different negative effects on the green development of the city;The high and low level of economic development are unfavorable to the development of green economic efficiency;The proportion of tertiary industry and the comprehensive utilization rate of solid pollutants have a positive impact on the efficiency of green economy.Based on the above research conclusions,counter measures and suggestions for the green development of urban agglomeration in the Yangtze River Delta are put forward.