中国试点ETS的碳减排效果评估——基于分省高耗能工业子行业数据的分析

评估中国试点碳排放权交易体系(ETS)碳减排效果的现有研究普遍存在处理组样本选取范围明显大于试点ETS实际覆盖范围的问题。因此,文中对研究样本进行了更为严格的甄别：将2005—2017年各省的六大高耗能工业子行业中纳入试点企业的体量占相应子行业体量60%及以上的工业子行业作为处理组,将非试点地区的工业子行业作为对照组。基于双重差分法的分析表明,相较于对照组,试点ETS在启动后不仅促进了处理组工业子行业碳排放绝对量的下降,还促进了其碳排放强度的下降,说明试点ETS具有明显的碳减排效果。工业子行业的总产值和人均总产值分别与其碳排放量和碳排放强度呈现出一定的库兹涅茨曲线效应,工业子行业资产的流动性越强、盈利能力越强、面临的环境规制强度越大,越有利于碳减排。建议主管部门坚定依靠市场手段来控制温室气体排放,尽快将更多行业纳入全国ETS;另外,应提高体系运行相关数据的公开力度,定期对体系进行分析评估,并及时公布评估结果。

Evaluation of the carbon emission reduction effect of China’s pilot ETSs: analysis based on the data of energy-intensive industrial sub-sectors by province

Existing studies evaluating the carbon emission reduction effect of China’s pilot emissions trading schemes (ETSs) suffer a common problem that the sample selection range of the treatment group is obviously larger than the actual coverage of pilot ETSs. Stricter criteria have been applied in identifying the research samples in this study: within the six energy-intensive industrial sub-sectors in China’s provinces from 2005 to 2017, only those in which the volume of ETS-covered enterprises accounts for 60% or more of the sub-sectors’ total are regarded as the treatment group, and all industrial sub-sectors in non-pilot provinces are the control group. Based on the difference-in-difference method, it is found that compared to the control group, China’s pilot ETSs have reduced not only the carbon emissions of the sub-sectors in the treatment group, but also their carbon intensities, demonstrating the mitigation effectiveness of China’s pilot ETSs. The gross output value and per capita output value of the industrial sub-sectors show to some extent a Kuznets curve effect with carbon emissions and carbon intensity, respectively; higher degree of asset liquidity and the profitability and tighter of environmental regulations is conducive to carbon emission reductions. It is thus essential that more sectors other than the power generation will be covered by China’s national ETS as soon as possible. In addition, more efforts should be made to disclose system design and operation data for the purpose of assessing the scheme performance more effectively and in a more transparently manner.