Green Total Factor Productivity and the Evolution of Intercity Innovation Networks: A Dual-Network Analysis Based on TERGM and VERGM in the Guangdong–Guangxi Region, China

Understanding the relationship between green total factor productivity (GTFP) and the evolution of intercity innovation networks (IINs) is important for sustainable development. Using co-authored papers and joint patent applications from 35 cities in Guangdong and Guangxi during 2012–2022, this study constructs intercity knowledge innovation networks (IKINs) and intercity technological innovation networks (ITINs), and measures GTFP with a super-efficiency SBM-GML model incorporating undesirable outputs. We examine the spatiotemporal evolution of GTFP and both networks, and employ the temporal exponential random graph model and valued exponential random graph model to investigate the factors associated with the evolution of the two networks in terms of tie existence and tie strength. Results show that: (1) average GTFP rises with fluctuations, with marked intercity and interprovincial disparities; (2) the density of IKINs is higher than that of ITINs, and both networks become more polycentric while retaining core–periphery structures; (3) tie existence in both networks exhibits significant temporal dependence and endogenous structural dependence, while prior collaboration strength is significantly and positively associated with current collaboration strength; (4) GTFP levels are significantly and positively associated with tie existence in both networks, but this association does not consistently extend to tie strength; and (5) industrial structure upgrading, geographical proximity, and institutional proximity are all associated with the evolution of both networks.