Abstract: Digital economy is playing an increasingly prominent role in promoting the economic growth and the changes of quality and efficiency. Based on the establishment of the dynamic theory of the impact of digital economy on urban economic growth, this paper conducts an empirical analysis by making use of the panel data of 254 cities in China from 2011 to 2019. The findings show that the impact of digital economy on economic growth has not only the dynamic effect, but also the spatial spillover effect. The data analysis indicates that the impact of digital economy on urban economic development of different regions has heterogeneity. The spatial spillover effect of the impact of digital economy on economic growth in the neighboring cities at the inter-provincial border is significantly higher than that in neighboring cities within the province, and the spatial spillover effect of digital economy in the neighboring cities in the central and western regions is significantly higher than that in the eastern region. The double difference estimation with the Broadband China as the policy shock further verifies the robustness of the above-mentioned conclusion. This shows that, unlike the traditional economic development modes, the input and accumulation of digital economy can release the constraints of geography and transportation, which will be more conducive to the agglomeration development of urban clusters and the construction of inter-provincial economic zones, especially the economic growth and the regional coordinated development in the central and western regions.

Key words: digital economy, urban economic growth, dynamic path, spatial spillover effect