Regional integration degree and its effect on a city’s green growth in the Yangtze River Delta: research based on a single-city regional integration index

Abstract

In recent years, China’s economy has shown a trend of coordinated regional development. The integrated construction of urban agglomeration as a space carrier has placed the coordinated governance of the regional environment on the agenda. As such, we need to determine the effect of a city’s degree of regional integration on environmental regulation and green total factor productivity. To this end, a single-city regional integration index based on commodity retail price index is constructed to measure the degree of regional integration. Different from the traditional indexes that measure the integration degree of multiple economies, the proposed index aims to measure the integration degree of a single city into a region. This study also examines the effect of the city’ degree of regional integration on the relationship between environmental regulation and green total factor productivity using panel data on the Yangtze River Delta’s urban agglomeration from 2003 to 2016 for empirical analysis. The results reveal the existence of a positive U-shaped relationship between environmental regulation and green total factor productivity, where the city’s degree of regional integration buffers this relationship. Differing from existed papers, this study provides an index to measure the degree of a single city’s integration into a region and identifies the buffer effect of this regional integration on the city’s green growth based on the urban agglomeration level.