How does digital economy affect green technological innovation in China? New evidence from the “Broadband China” policy

This paper investigates the nexus between digital economy and green technological innovation by utilizing the panel data from 284 cities of prefecture and above from 2010 to 2019. To examine this relationship, we develop an extensive framework that incorporates the multi-period DID model, the PSM-DID model, the mediating effect model, and the spatial DID model. Furthermore, we treat the "Broadband China" policy as a quasi-natural experiment and measure green technological innovation from both quantity and quality perspectives.Finally, we gain the following conclusions: (1) Digital economy can simultaneously advance the quantity and quality of green technological innovation, and these impacts remain valid after removing influences from other policies. (2) The mediating effect of government R&D funding intensity and marketization level has been partially verified, with marketization level not significantly affects the interaction between digital economy and the quality of green technological innovation. (3) Digital economy not only stimulates green technological innovation in pilot cities, but also has a positive effect on non-pilot cities neighboring these cities. (4) Heterogeneity test of both non-spatial and spatial spillover effects are respectively supported at regional and administrative levels. Accordingly, several policy measures are proposed, including enhancing policy design capacity, expediting the construction of a market-based system for green innovation, and dismantling regional and administrative obstacles.