Coupling Effect of the Energy–Economy–Environment System in the Yangtze River Economic Belt

The Energy–Economy–Environment (3E) nexus within basin economic zones has received significant scholarly attention. As a major river basin economic belt in China, the Yangtze River Economic Belt (YREB) serves as an important case for examining the status and drivers of coordinated 3E development. The findings of this study may also offer valuable insights for promoting sustainable development in river basin economies globally. Encompassing 11 provinces and municipalities, the YREB represents not only a vital socioeconomic region in China but also one of the nation’s largest energy consumers, facing considerable environmental pressures. Using panel data spanning 2009–2019, this study applies the coupling coordination degree (CCD) model, spatial Durbin model, and Moran’s I to assess the coordination level of the 3E system in the YREB. The main findings are as follows: (1) The CCD demonstrated a trend that was fluctuating but generally on the rise throughout the study period. Higher values were observed in eastern provinces and lower ones in western provinces, which reveals a distinct east–west spatial gradient. (2) A significantly positive spatial correlation was observed in provincial 3E coordination, although this correlation fluctuated and showed a slowly weakening trend over time. Local spatial clustering patterns also shifted, marked by the persistence of high-high clusters, an increase in low-low clusters, and the emergence of low-high outliers. (3) Estimates from the spatial Durbin model indicate that urbanization, automobile consumption, and foreign trade exert positive overall effects on the CCD, whereas industrial structure exerts a negative overall effect. Environmental policy is not statistically significant in the static model but shows a negative overall effect when the CCD is lagged by one period.