Does industrial co-agglomeration promote green energy efficiency? Evidence from spatial panel data of 284 cities in China

Industrial co-agglomeration (IC) plays a pivotal role in the development of local and adjacent green energy efficiency across 284 Chinese cities, encompassing both resource-based and non-resource-based urban centers. Based on the panel data of 284 cities in China from 2005 to 2020, this study employs spatial econometric methods to empirically assess the influence of IC and its spillover effects on green energy efficiency, employing a spatial Durbin model. Additionally, the study categorizes the 284 Chinese cities into resource-based and non-resource-based categories, utilizing spatial econometric methods to delve into the heterogeneity of their effects and spillover impacts. The key findings are as follows: (1) The average green energy efficiency across the 284 Chinese cities from 2005 to 2020 stands at 0.5834. The trend in IC indicates growth and concentration towards the central areas, increasing from 2.7396 in 2005 to 2.7658 in 2020. (2) The IC, with a coefficient of 0.0918, promotes the local green energy efficiency. (3) There are spillover effects of local IC on the green energy efficiency in adjacent areas with a coefficient of 0.2550 and an Indirect Effect of 0.4567. (4) In resource-based cities, IC positively impacts local green energy efficiency with a coefficient of 0.1056 but negatively affects green energy efficiency in adjacent areas with a coefficient of −0.1368. In non-resource-based cities, IC enhances green energy efficiency in adjacent cities with a coefficient of 0.1335. Consequently, the study offers pertinent policy recommendations aimed at improving energy efficiency in light of these findings.