Dynamic evolution of green innovation efficiency in China: spatial heterogeneity and convergence analysis

Green innovation plays a pivotal role in fostering sustainable and robust economic growth. Hence, it is of great practical significance to accurately assess green innovation efficiency and analyze its evolving trends and discrepancies from a spatiotemporal dynamic perspective. This study analyzes the green innovation efficiency across 30 provinces in China from 2001 to 2019 using the Super-SBM model, Dagum Gini coefficient, Kernel density estimation, and convergence models. The results reveal a consistent enhancement in China's green innovation efficiency, yet substantial room for further improvement persists, standing at 0.679 in 2019. Both China as a whole and its four major regions exhibit a polarisation trend in green innovation efficiency, characterised by notable internal disparities, albeit displaying a declining pattern. Interregional divergence is the primary source of the overall disparity, followed by intraregional disparities and the intensity of transvariation. China's green innovation efficiency demonstrates sigma and beta convergence trends. The study also highlights how uneven regional development and resource allocation disparities lead to an imbalanced convergence of regional green innovation efficiency.