Does the opening of high-speed rail speed up the development of urban digital economy?

Using the multi-period DID model, we investigated the impact of high-speed rail (HSR) on the urban digital economy. We found that the opening of HSR can indeed improve the urban digital economy, and this conclusion remains after a set of robust checks. Mechanism analysis demonstrated that the enhancement effect of HSR on the urban digital economy is mainly achieved by promoting regional innovation and generating financial agglomeration. Heterogeneity analysis revealed that this effect is more pronounced in cities with well-developed digital infrastructure and cities with high governmental expenditure. In addition, we also confirmed a positive spillover effect, i.e., that the opening of HSR can not only significantly improve the urban digital economy in local cities but also enhance its development in neighboring ones.