How does digital technology empower urban green development efficiency in the Beijing-Tianjin-Hebei region—mechanism analysis and spatial effects

Under the strategy of “Digital China” and “Sustainable Development,” the synergistic development of digital economy and green economy has become a crucial topic. Based on the panel data of 13 cities in the Beijing-Tianjin-Hebei (BTH) region from 2011 to 2019, this study investigates the direct effect, intrinsic mechanism, and spatial spillover effect of digital technology development (DTD) on urban green development efficiency (GDE). The empirical results show that (1) DTD significantly improves urban GDE in the BTH region, and it passes the endogeneity test, (2) DTD can enhance urban GDE by improving the environmental regulation intensity and technological innovation level in the BTH region; however, the industrial structure optimization weakens the promotion effect of DTD on urban GDE in the BTH region, which shows a “masking effect,” (3) the kernel density estimation method and ArcGIS technology reveal the existence of “digital divide” and GDE differences among cities in the BTH region. Moreover, the spatial distribution pattern of DTD gradually forms “H–H” and “L-L” clusters in the BTH region, and (4) DTD also increases the GDE of neighboring cities through spatial spillover effects in the BTH region, and it passes the robustness test of replacing the spatial weight matrix. This study is important for the BTH region to simultaneously solve economic development and environmental problems in the context of digitalization.