China’s urban green innovation: Regional differences, distribution dynamics, and convergence

Urban green innovation (UGI) is essential to environmental protection, ecological conservation, and high-quality economic growth. Using green patents, our study assessed the level of UGI of 287 Chinese cities at and above the prefecture level. Then, using the Dagum Gini coefficient, kernel density estimation (KDE), and convergence models, we examined regional differences, distribution dynamics, and convergence of UGI across China. The study’s findings are as follows: (1) Overall, regional differences in UGI tended to narrow, and the main contributor to these differences was the difference between economic zones. (2) KDE showed that the level of UGI was rising, which was polarized within each economic zone. (3) The national UGI in economic zones other than the Northeast and Middle Yellow River Economic Zones featured significant σ convergence, while each economic zone showed absolute and conditional β convergence