The Impact of the Low-Carbon City Pilot Policy on Energy Intensity: Evidence from a Staggered Difference-in-Differences Design

Under China’s dual-carbon agenda, a central question is whether the Low-Carbon City (LCC) pilot policy reduces energy intensity, whether this effect can be credibly interpreted as causal, and under which conditions and through which channels it operates. Using a balanced panel of 282 prefecture-level and higher-level cities from 2006 to 2023, this study develops a problem-oriented framework that integrates effect identification, credibility validation, and heterogeneity and mechanism analysis. The average treatment effect is estimated using staggered difference-in-differences, while dynamic effects are identified with interaction-weighted and imputation-based event-study estimators, and selection concerns are further addressed through propensity score matching difference-in-differences and a battery of stability checks. The results show that the LCC pilot policy reduces urban energy intensity, with the baseline estimate implying a decline of about 15%–16%, and that the policy effect accumulates over time rather than appearing immediately. This finding remains stable across alternative specifications, placebo tests, and matched-sample estimation. The policy effect is stronger in cities with higher initial energy intensity and higher levels of economic development. Mechanistic evidence indicates that adjustments in fixed asset investment and changes in AI-related resource allocation are two observable channels associated with the decline in energy intensity. By focusing on energy intensity as a process-oriented performance indicator, this study provides more direct evidence on the energy-efficiency consequences of low-carbon urban governance and clarifies the conditional and structural foundations of policy effectiveness.