Does regional integration strategy promote green innovation? Evidence from China's Yangtze River Delta integration

The implementation of regional integration strategy has facilitated the rapid development of the regional economy and society; however, its potential to promote green innovation within the region still requires further investigation. Focusing on China's macro-regional strategy of the Yangtze River Delta (YRD) integration, this study treats its rollout as a quasi-natural experiment. We empirically investigate its effect on green innovation by applying a multi-period difference-in-differences model to urban panel data (2004–2020) from six provinces and one city in East China. And the intermediary influence mechanism was analyzed by TOE theoretical framework. The results show that the YRD integration strategy can significantly promote urban green innovation, and the effect is more significant for the cities with a population of <5 million. The YRD integration strategy can promote urban green innovation by improving the information level, increasing government support and strict environmental regulations.