Abstract: Digital infrastructure construction is the basic foundation for cities to accelerate the development of new quality productivity. Based on the prefecture panel data of 284 cities over the period from 2010 to 2022, the empirical analysis takes the “Broadband China” strategy as a quasi-natural experiment and tests the impact of digital infrastructure construction on the new quality productivity of urban development and its mechanism. The research findings indicate that the digital infrastructure construction is conducive to the development of new quality productivity in cities. Under the influence of network effects and positive externalities, the digital infrastructure construction can improve the development level of urban new quality productivity by stimulating urban green technology innovation, improving the degree of agglomeration of enterprises above designated size in cities, and accelerating the evolution of industrial structure upgrading. This research quantitatively evaluates the economic effect of digital infrastructure empowering cities to develop new quality productivity. It provides a useful reference for the development of new quality productivity according to local conditions.

Key words: digital infrastructure construction, new quality productivity, Broadband China, generalized difference-in-differences