Synergistic effect of carbon abatement and energy saving of digital infrastructure in China: Evidence from 284 cities

Digital infrastructure construction is paving an explorable path for carbon abatement and energy saving. Whether China's Broadband China Strategy (BCS) contributes to carbon abatement and energy saving is yet to be explored in depth. Using the dataset of 284 cities during 2010–2021 in China, this research applies staggered difference-in-differences (DID) to assess whether and how the BCS affects carbon abatement and energy saving. The results show that BCS significantly promotes the city's carbon abatement and energy saving, but the beneficial effects do not appear until the fourth year of the BCS implementation. The promotion of the BCS demonstration cities has contributed to carbon abatement and energy saving mainly by expanding scale aggregation, optimizing resource allocation, and stimulating low-carbon innovation related to energy. Heterogeneity analysis reveals that the carbon abatement and energy saving effects of BCS are more noticeable in eastern and larger economic scale cities. Non-resource-based cities benefit more from BCS's carbon abatement effects, while resource-based cities benefit more from BCS's energy saving effects. Furthermore, BCS shows a siphon effect on carbon abatement and energy saving in geographically neighboring cities, while it shows a demonstration effect in economically neighboring cities.