How does the development of digital economy in central cities promote the coordinated development of regions? Evidence from 19 urban agglomerations in China

Externality is the power source of the spillover effect of digital economy development in China's central cities. Based on panel data of 200 prefecture-level cities in 19 urban agglomerations in China from 2011 to 2020, this research constructs a theoretical model with income output, labor, and capital input and adopts the panel fixed effect model to empirically test the impact of central cities' digital economy development on peripheral cities' urban agglomerations. The results are as follows. First, digital economy development in central cities significantly improves the level of such development in peripheral cities. Second, the spillover effect of this development in central cities is affected by their own geographical location, economic development level, and city size. Third, the spillover effect of digital economy development in central cities mainly arises through the learning mechanism.