Spatial-temporal differentiation of urban eco-efficiency in the Yangtze River Economic Belt and its driving factors.

Clarifying the spatial-temporal differentiation of urban eco-efficiency and its driving factors is the primary task of achieving green and sustainable development in the Yangtze River Economic Belt. Based on the urban panel data from 2003 to 2018, this paper used the MinDS model to measure the eco-efficiency of cities in the Yangtze River Economic Belt, revealed the specific sources of urban ecological inefficiency from the perspective of input-output, and further used the Theil Index and geographic detectors to empirically investigate the spatial-temporal differentiation characteristics and driving factors of its urban eco-efficiency. The study found that: (1) During the sample period, the overall eco-efficiency of the Yangtze River Economic Belt and the cities in the upper, middle and lower reaches showed a rising trend of fluctuation, and the downstream area was always higher than the middle and upstream areas. Insufficient expected output and undesired output redundancy were the root causes of urban ecological inefficiency. (2) Intra-regional differences were the main source of spatial differences in urban eco-efficiency in the Yangtze River Economic Belt. Before 2011, the differences in internal eco-efficiency in the downstream regions had the greatest impact on the overall differences; after 2011, the differences in the downstream and upstream regions alternately ranked first and second in the contribution list. (3) The absolute difference in urban eco-efficiency in the middle and lower reaches of the Yangtze River had decreased significantly, but the upstream area expanded slightly. Except for the middle reaches of the Yangtze River, urban eco-efficiency in the Yangtze River Economic Belt demonstrated a certain gradient effect, and polarization in the downstream area was the most obvious. (4) The spatial differentiation of urban eco-efficiency in the Yangtze River Economic Belt was affected by a variety of factors. From the perspective of structural factors, the difference in economic development had always been the most decisive factor for the spatial differences in the urban eco - efficiency of the Yangtze River Economic Belt. The difference in energy input and pollution emissions had a relatively small effect; from the perspective of socioeconomic factors, the difference between population density and the spatial differentiation of urban eco-efficiency was significantly stronger than other factors. [ABSTRACT FROM AUTHOR]