Digitalization Policy and Green Energy Productivity: How Policy Synergy Accelerates Energy Transition in Chinese Cities?

Digitalization is increasingly regarded as a driving force for urban green transition, yet much less is known about whether digitalization policies operate in isolation or interact with complementary digital and low-carbon policies in improving urban green energy productivity (GEP). Taking the National E-commerce Demonstration City (NEDC) policy as a quasi-natural experiment, we study a balanced panel of 274 prefecture-level Chinese cities over 2008–2022 using a multi-period difference-in-differences design, complemented by estimators that are robust to staggered adoption and heterogeneous treatment effects. We find that the NEDC policy is associated with a statistically significant increase in urban GEP of about 4.2 percentage points. The evidence is consistent with three channels: accelerated energy transition, industrial upgrading, and the agglomeration of high-tech enterprises. The estimated effect is more pronounced in non-resource-based cities, economically developed regions, and key environmental protection cities. The interactions between the NEDC policy and the New Energy Demonstration City program, the National Big Data Comprehensive Pilot Zone policy, and the Broadband China Strategy are all positive and statistically significant, with larger estimated NEDC effects where these companion policies are concurrently active. This study provides empirical implications for emerging economies pursuing dual goals of digitalization and decarbonization.