Based on carbon emission data from 38 two-digit industrial sectors across 133 cities from 2009 to 2020, this study reappraises the carbon reduction effects of low-carbon city pilot policies using a difference-in-differences approach and explores potential mechanisms through resource allocation and technological innovation. The results indicate that low-carbon pilot policies significantly reduce carbon intensity at the city-sector level. Optimized land resource allocation serves as an important channel for the policy’s impact, while the level of technological innovation also plays a critical role in the emission reduction process. The carbon reduction effect is more pronounced in cities with greater fiscal pressure or lower dependence on land finance, as well as in medium-low technology, labor-intensive, and capital-intensive sectors. The policy exhibits a stronger emission reduction effect in high-carbon industries. This study helps to unveil the implementation mechanism of low-carbon policies at the city-sector level and provides theoretical insights for exploring localized low-carbon development pathways.

基于2009—2020年133个城市的38个二位数工业行业碳排放数据, 采用双重差分法, 对低碳城市试点政策的碳减排效应进行再评估, 并从资源配置与技术创新两个维度探讨其潜在作用机制。结果表明, 低碳城市试点政策显著地降低“城市–行业”层面的碳排放强度; 土地资源配置优化是低碳城市试点政策发挥作用的重要路径之一, 技术创新关联水平在碳减排过程中亦具有重要作用; 这项政策在财政压力较大或土地财政依赖程度较低的城市以及中低技术层次、劳动密集型和资本密集型行业中产生的碳减排效应更显著, 对高碳行业的减排效果更突出。研究结果有助于揭示“城市–行业”尺度下低碳政策的实施机制, 为探索地方低碳发展路径提供理论参考。