Enhancing Sustainability Through Regional Integration: A Quasi-Natural Experiment on Green Innovation of Listed Firms in the Yangtze River Delta

Enhancing corporate green innovation has become a critical question in the context of sustainable development. Prior studies have predominantly examined the macro-level effects of regional integration while largely overlooking its micro-level impacts on enterprises. This study aims to examine the institutional effect of regional integration on corporate green innovation. Taking the Yangtze River Delta integration as a quasi-natural experiment, we utilize panel data from A-share listed companies between 2003 and 2022 and apply a multi-period difference-in-differences method. The empirical results reveal that regional integration significantly enhances corporate green innovation, with a more pronounced effect for non-state-owned firms, large firms, and those located in non-corridor cities. Mechanism analyses further reveal that regional integration promotes corporate green innovation by alleviating financing constraints and attracting foreign direct investment. By identifying regional integration as a critical driver of corporate green innovation, this study broadens the research perspective on corporate green innovation and provides policy implications for promoting sustainability through coordinated regional development strategies.