Digital infrastructure construction, carbon total factor productivity, and carbon rebound effect.

Digital infrastructure construction (DIC) and low-carbon transformation are important engines and objective functions of the superior economic development, and the synergistic drive between the two is essential to achieving lasting economic development. Based on the panel data of 279 cities in China between 2007 and 2019, the econometric model system is used to explore the impact mechanism of DIC on carbon total factor productivity (CTFP), and the impact of DIC on carbon rebound effect (CRE) is further studied. Research findings that, first, the expansion of DIC has a nonlinear effect on CTFP, with a U-shaped link between the two; multiple robustness tests confirm that this is still true. Second, DIC and optimization of the energy consumption structure in a "U" curve relationship, and the major strategy for increasing CTFP is to reduce energy consumption, while industrial structure optimization and technical innovation have less of a intermediary effect. Third, further analysis reveals that there is a "U" shaped nonlinear connection between the DIC and the CRE, and energy savings and emission reductions in the later stages of DIC fall short of expectations. The current DIC is still dominated by episodic expansion. The findings of the study can better enhance CTFP, curb the CRE, put a limit on total carbon emissions and accelerate the decoupling of economic growth from carbon emissions.