No abstract

Cities enhance the efficiency of green development among themselves through their borrowing population, economic activities density and advanced functions, but the positive green effect of the borrowing size is affected by the city size. Using panel data of 280 prefecture-level cities in China for the period 2009–2019, this paper measures the borrowing size in three dimensions, namely the borrowing population size, borrowing economic activity density and borrowing advanced functions, and uses the super efficiency slacks-based measure (SBM) model, including non-desired outputs, to measure the urban green development efficiency. After that, this paper empirically examines the effect of the borrowing size on the urban green development efficiency in the Chinese urban network using a double-fixed-effect model. A panel threshold regression with city size as the threshold variable is conducted to evaluate the nonlinear relationship quantitatively between the borrowing size and urban green development efficiency. The results show that all three dimensions of the borrowing size have positive effects on the urban green development efficiency. There is a significant double-threshold effect between the borrowing size and urban green development efficiency; under the threshold of the city size, there is a U-shaped relationship between the borrowing population size, borrowing advanced functions and urban green development efficiency, whereas there is an inverted U-shaped relationship between the borrowing economic activity density and urban green development efficiency. Accordingly, this paper argues that government should pay attention to the role of the borrowing size in promoting urban green development efficiency and reasonably expand the city size.