Impact of the green economic efficiency on industry-urban integration in the Yangtze River delta region

Industry-urban integration (IUI) is an innovative strategy that has emerged as a pivotal pathway for promoting resource and environmental management. Green economic efficiency (GEE) represents a major trend in global economic transformation and significantly impacts IUI, warranting further investigation. Drawing on data from the Yangtze River Delta region from 2012 to 2023, this study employs heterogeneity analysis, mediating effect, and threshold effect mechanisms to comprehensively evaluate the GEE’s role in IUI. The findings reveal the following key insights: First, the impact of GEE on IUI varies across regions, with a stronger effect in economically developed areas and non-resource-based urban areas with green economic efficiency policies. Second, the mediating effect identifies the improvement strategies of the GEE that indirectly drive IUI by enhancing government fiscal decentralization (GFD). Third, the relationship between the GEE and IUI demonstrates a threshold effect driven by technological innovation (Tech). Upon TECH capability rising above a critical level, the beneficial influence of GEE on IUI becomes markedly more evident. This study offers policy recommendations to advance both the GEE and IUI, contributing to the integration of environmental, economic, and societal strategies.