An Empirical Investigation into the Effects of the Digital Economy on Regional Integration: Evidence from Urban Agglomeration in China

Based on the urban panel data of Beijing-Tianjin-Hebei from 2009 to 2021, this article constructs an indicator system for the development level of the digital economy and regional integration, evaluates the impact of the digital economy on the integration development levels of different types of cities. The study found that (1) The digital economy significantly promotes the integration level of Beijing, Tianjin, and Hebei. The study divides Beijing-Tianjin-Hebei into two categories: large cities and small and medium-sized cities. Large cities and small and medium-sized cities have different effects on the relationship between the digital economy and integration level. (2) From the analysis of different dimensions of the digital economy, digital network infrastructure improvements, industrial digitization, and digital society can all promote regional integration. However, different digital economy contents have different promotional effects on different types of cities. (3) From the results of the mechanism analysis, it can be seen that the optimization of the allocation of human and capital elements, the increase in patent innovation, and the reduction of transaction costs will help enhance the driving force of the digital economy for regional integration. Among them, innovative development significantly impacts large cities' integration levels. The promotion effect is more significant, and small and medium-sized cities are mainly affected by reduced transaction costs and the optimized allocation of capital factors. This study further expands the impact mechanism of the digital economy on the level of regional integration development. It provides a more in-depth analysis of the use of the digital economy to achieve coordinated regional development in regions with excessive economic and technological differences through heterogeneity research.