Measurement of Urban Green Total Factor Productivity and Analysis of Its Temporal and Spatial Evolution in China

This paper uses the Super SBM-DEA model and GML index method with undesirable output indicators to measure GTFP in 288 cities in China. Furthermore, we divide Chinese land into east, central, west, and northeast parts, and analyze their temporal and spatial evolution trends. It is shown that, firstly, China's overall GTFP shows an upward fluctuating trend, in which green technical efficiency contributes more to the improvement of GTFP in Chinese cities, while green technological progress contributes less. Secondly, the urban GTFP in the eastern, central, western, and northeastern regions shows obvious differences, with the source of GTFP growth in the eastern region being mainly green technological progress, the source of growth in the central region being green efficiency improvement in the early stage and green technological progress in the later stage, while the source of growth in the western and northeastern regions is green efficiency improvement. Finally, combined with spatial distribution characteristic maps and kernel density estimation, GTFP shows spatial disequilibrium characteristics in China.