Abstract: As the key driving force for the development of the current digital economy era, digital technology innovation cannot be separated from the support of the social credit system. This paper constructs a quasi-natural experiment with the National Social Credit System Construction Pilot Cities, it employs a multi-period difference-in-differences (DID) model to evaluate the impact of credit city construction on enterprise digital technology innovation. The empirical research finds that the credit city construction significantly promotes enterprise digital technology innovation, with a more pronounced effect on enterprise digital invention patent applications. The research conclusions remain robust after a series of robustness checks and with the consideration of endogeneity issues. The significance lies in three mechanisms: R&D investment, agency costs, and credit financing. Heterogeneity tests reveal that the policy effects are more significant for state-owned enterprises, capital-intensive and technology-intensive enterprises, and enterprises in regions with higher levels of legal environment. This study not only effectively evaluates the policy effects of credit city construction in promoting enterprise digital technology innovation but also provides practical evidence for the role of credit city construction as an essential support for digital China construction and digital economic development.

Key words: credit city construction, enterprise digital technology innovation, policy effect evaluation, multi-time point difference-in-difference model