碳排放交易制度下城市减排的机会成本研究——基于中国碳排放试点城市的实证检验

作为全球气候治理的重要手段，碳排放交易制度受到了广泛的关注与讨论。基于此，本文采用我国2010-2016年城市面板数据，运用非参数方法构建方向性环境距离函数测算了2009-2015年城市减排的机会成本，计算结果显示，试点地区与非试点地区的碳排放的机会成本整体表现为上升的趋势，且试点地区的碳排放的机会成本总体低于非试点地区。在测算城市减排机会成本的基础上，运用双重差分法来检验碳排放交易制度的有效性。经检验发现：碳排放交易制度有利于降低城市减排的机会成本，然而由于碳排放交易制度还存在碳排放权初始分配制度缺失、碳排放交易制度的定价机制扭曲等问题，因此其对降低城市减排的机会成本作用较小，并且进一步通过对政策时间趋势的分析得出政策效应随时间推移而逐渐减弱。

Research on Opportunity Cost of Urban Emission Reduction Under Carbon Emission Trading System: Empirical Test Based on China's Carbon Emission Pilot Cities

As an important mean of global climate governance, carbon emissions trading system has been widely concerned and discussed.Based on China''s 2010-2016 urban panel data, a non-parametric method is used to construct a directional environmental distance function to measure the opportunity cost of urban emission reduction in 2009-2015. The calculation results show that the opportunity cost of carbon emissions in pilot areas and non-pilot areas is generally increasing, and the opportunity cost of carbon emissions in pilot areas is generally lower than that in non-pilot areas. On the basis of calculating the opportunity cost of urban emission reduction, this paper uses difference-in-difference method to test the effectiveness of carbon emissions trading system. It is found that the carbon emission trading system is conducive to reducing the opportunity cost of urban emission reduction. However, there are still some problems in the carbon emission trading system, such as the lack of the initial allocation system of carbon emission rights, the distortion of the pricing mechanism of the carbon emission trading system and so on. Therefore, it has less effect on reducing the opportunity cost of urban emission reduction, and further through the analysis of policy time trend, the policy effect gradually weakened over time.