Spatiotemporal evolution characteristics and influencing factors of energy-ecology-economy complex system efficiency: Case study of Yangtze River Economic Belt in China

Given the growing concern over global warming, the issue of balancing ecological preservation with economic development is receiving increased attention from researchers and policymakers. This paper uses the two-stage NDEA-SBM model to calculate the energy, ecology, and economic (3E) efficiency of the Yangtze River Economic Belt (YREB) and analyze the spatial distribution characteristics and influencing factors of 3E. The main results are as follows: (1) The 3E efficiency in the YREB demonstrates a gradual improvement, increasing from 0.65 in 2011 to 0.75 in 2020. The most 3E efficient cities are mainly concentrated in the middle and lower reaches of the YREB. (2) Before 2014, the highest efficiency of 3E was in the upper reaches, followed by the middle reaches, and then the lower reaches. After 2014, the middle reaches were the highest, followed by the lower reaches, with the upper reaches being the lowest. (3) The center of gravity of 3E efficiency gradually moves to the lower reaches, and the moving range is mainly concentrated in the middle reaches, signifying a decline in 3E efficiency in the upper reaches and an increase in the lower reaches. (4) The efficiency of 3E is positively correlated with manufacturing scale, economic development, and government intervention, and negatively correlated with financial development and opening up. This study provides new insight into the contradiction between economic development and environmental protection.