Results of descriptive statistics for variables.

Low-carbon pilot policies are an important way to achieve the goal of "peak carbon neutrality" and are of great significance to China’s international commitments. Based on a sample of 282 prefecture-level cities from 2006 to 2020, this paper investigates the impact of low-carbon pilot policies on urban carbon efficiency using a quasi-natural experiment with three batches of low-carbon pilot cities in 2010, 2012, and 2017, respectively. It is found that: (1) low-carbon pilot cities can improve urban carbon emission efficiency, which is still valid after a series of robustness tests such as the parallel trend test, placebo test, PSM-DID, and counterfactual test; (2) low-carbon pilot cities can enhance urban carbon emission efficiency by promoting the level of urban innovation and advanced urban industrial structure; and (3) the impact of low-carbon pilot policies on urban carbon emission efficiency is heterogeneous across cities with different geographical locations, population sizes, and resource endowment types. The findings provide policy insights for the promotion of low-carbon pilot policies and strengthening the construction of low-carbon pilot cities.

低碳试点政策是实现‘碳达峰碳中和’目标的重要路径，对我国履行国际减排承诺具有重要意义。本文以2006-2020年282个地级市为研究样本，借助2010年、2012年、2017年先后三批次获批的低碳试点城市这一准自然实验场景，考察低碳试点政策对城市碳排放效率的影响效应。研究发现：其一，低碳试点政策可有效提升城市碳排放效率，该结论通过平行趋势检验、安慰剂检验、倾向得分匹配-双重差分法（PSM-DID）以及反事实检验等一系列稳健性检验后依然成立；其二，低碳试点政策可通过提升城市创新水平、推动城市产业结构向高级化演进，进而改善城市碳排放效率；其三，低碳试点政策对城市碳排放效率的影响效应存在显著异质性，该异质性体现在不同地理区位、人口规模以及资源禀赋类型的城市之间。本研究结论可为推广低碳试点政策、深化低碳试点城市建设提供政策启示。