Synergistic effect of the low-carbon city and sci-tech finance pilots on green innovation in China

Global warming has become a critical environmental issue that continues to attract worldwide attention. To promote low-carbon development, China has introduced a series of emission-reduction policies. Against this backdrop, this study investigates the impacts, underlying mechanisms, synergistic effects, and heterogeneity of dual-pilot policies on green innovation, focusing on low-carbon city (LCC) policy and sci-tech finance city (STFC) policy. The analysis draws on data for 278 Chinese cities from 2006 to 2021 and employs a multi-period DID model. The results reveal that the dual-pilot policies of the LCC and STFC significantly promote both substantive green innovation (SUGI) and strategic green innovation (STGI) in pilot cities. Mechanism tests suggest that the dual-pilot policy stimulates green innovation indirectly by increasing government financial support for technology, strengthening environmental regulation, and fostering the agglomeration of venture capital. The synergy analysis further indicates that the dual-pilot policy is more effective in promoting green innovation than either single-pilot policy, with the sequencing of “STFC first, then LCC” yielding the strongest effect on SUGI. The positive impact of the dual-pilot policy is more pronounced in cities with larger populations, those located in the eastern and central regions, and those with stronger environmental foundations. Finally, this study offers policy recommendations to enhance the synergy between LCC and STFC initiatives for sustainable urban development.