Chengkun LIU, Mengyu YAN, Minghong ZHANG
Green innovation, as the integration of the “green” and “innovation” themes under the concept of high-quality development, is an important pathway to drive China’s economic growth and enhance its international industrial competitiveness. This paper based on panel data from 214 prefecture-level cities from 2007 to 2022, this study first employs a multi-period synthetic difference-in-differences approach to examine the impact of low-carbon city pilots, innovative city pilots, and dual “low-carbon–innovation” policy pilots on green innovation. The study then further compare the policy effects of the dual pilot sequence on green innovation, and analyze in depth the heterogeneous characteristics of the impact of the pilot sequence on green innovation in different city locations, scientific and educational levels, and city levels. Finally, a spatial difference-in-differences model is constructed to explore the spatial spillover effects of the dual policy pilots. The findings reveal that low-carbon city pilots, innovative city pilots, and dual policy pilots all significantly promote green innovation, with the dual policy pilots demonstrating stronger policy effects compared to single pilots, and the effects of both single and dual pilots progressively strengthen over time. Overall, the policy of innovation first and low carbon later exhibits a greater promoting effect on green innovation levels compared to “low carbon first, then innovation”. The impact of the implementation sequence of the dual policies on green innovation varies depending on geographical location, urban level of science and education, and urban level heterogeneity. Specifically, the policy of low carbon first and innovation later fosters green innovation in eastern regions and cities with moderate levels of scientific and educational development, while the policy of innovation first and low carbon later shows larger innovation effects in eastern regions, cities with high levels of scientific and educational development, and key cities. Furthermore, the dual policy pilots demonstrate significant positive spatial spillover effects on neighboring regions and areas with similar levels of economic development. The research conclusions enrich the study of the economic effects of dual-policy pilot programs, while providing significant empirical evidence and policy references for the country to achieve high-quality development and comprehensive transformation and upgrading.