Can e-commerce reduce urban CO₂ emissions? Evidence from National E-commerce Demonstration Cities policy in China

The existing studies ignore the potential impact of e-commerce on CO₂ emissions. Based on panel data of 284 cities at the prefecture level and above in China from 2003 to 2019, we regard National E-commerce Demonstration Cities (NEDC) policy as a quasi-natural experiment and empirically examine the impact and mechanism of NEDC policy on urban CO₂ emissions by using multi-period difference-in-difference (DID) model and mediating effect model. The results show that, under the premise of satisfying parallel trends, the NEDC policy significantly reduces urban CO₂ emissions. Compared with the non-pilot cities, the NEDC policy leads to decreases in urban CO₂ emissions by 0.83%. The result still holds after a series of robustness tests, which include placebo test, propensity score matching (PSM) DID estimation, and instrumental variable estimation. The NEDC policy reduces urban CO₂ emissions through promoting industrial structure upgrading, green technology innovation, and economic agglomeration. Heterogeneity analysis shows that the reduction effect of NEDC policy on urban CO₂ emissions is stronger in non-western cities, larger scale cities, and resource-based cities.