碳排放权交易政策对企业绿色技术创新的影响--基于工具变量和三重差分的检验

The Impact of Carbon Emission Trading Policy on Firms'Green Technology Innovation:Based on Instrumental Variables and Triple Difference Test

碳排放权交易政策能否激发企业绿色技术创新,对实现环境绩效和经济绩效的双赢至关重要。运用准自然实验研究法,考察了碳排放权交易试点政策对企业绿色技术创新的激励机制。研究发现:(1)在基准回归基础上,运用工具变量克服内生性问题、三重差分方法剔除其他政策影响以及一系列稳健性检验后,碳排放权交易政策仍能显著激发企业绿色技术创新,包括高质量绿色技术创新和低质量绿色技术创新。(2)进一步研究表明,宏观市场需求、中观行业竞争和微观企业内部控制等因素均能强化碳排放权交易试点政策的创新激励作用。(3)从企业所有制类型来看,相较于非国有企业,国有企业对碳排放权交易试点政策更加敏感;从资源禀赋来看,在资源禀赋短缺地区,碳排放权交易试点政策对企业绿色技术创新的激励更显著。

Achieving carbon peaking in 2030 and achieving carbon neutrality in 2060 is China's commitment to take responsibility for reducing greenhouse gas emissions.It raises China's green development to a new level.A win-win situa-tion for the economy and environment becomes the key target for future economic and social development.The pilot of the carbon emission trading system is China's market-oriented policy practice to promote green development.Whether it can stimulate firms'green technology innovation is directly related to the policy's market and emission reduction values.Therefore,this paper scientifically evaluates the impact of the carbon emissions trading system on firms'green technology innovation through empirical research.Based on the panel data of 121 listed companies in key carbon emission industries from 2008 to 2017,and taking the pilot policy of carbon emission trading system implemented in 2013 as the research object,a quasi-natural experiment of policy impact is constructed.Firstly,a parallel trend test is used to verify the feasibility of the research data and method.Secondly,a difference-in-difference model is built to evaluate the impact of carbon emission trading system on firms'green technology innovation.According to whether the firm belongs to the pilot area,the sample firms are divided into the experimental group and the control group,among which the firms belonging to the pilot area are the experimental group,otherwise the control group.The number of green patent applications measures a firm's green technology innovation.Thirdly,the dynamic window,instrumental variable,and triple-difference model are used to analyze the dynamic effect,endogeneity problem,and net policy effect of carbon emission trading system.In the instrumental variable test,the annual average temperature of the province is used as the instrumental variable.The triple-difference model adds 163 listed companies in non-carbon emission key industries as the data basis.Fourthly,the robustness of the econometric model is verified by replacing the dependent variable,changing the estimation method,counterfactual testing,and placebo testing.Finally,in order to deeply and comprehensively analyze the impact mechanism of carbon emission trading system on firms'green technology innovation,further analysis is organized to explore the moderating effect of macro,medium and micro environment and the heterogeneity of the incentive effect of the policy due to enterprise ownership and resource endowment.In the difference-in-difference model,the coefficient of the policy dummy variable is significantly positive.It indicates that the pilot policy of carbon emission trading system has a significant positive impact on firms'green technology innovation.And this result has passed multiple robustness tests.From the dynamic effects,the incentive effect of the carbon emission trading system on firms'green technology innovation begins to appear when the time window is expanded to 3 years,indicating that the incentive effect of the policy had a time effect.The results of instrumental variables and the triple-difference method show that the difference-in-difference model is still valid after overcoming endogeneity and excluding other policy influences.Further analysis shows that large-scale market demand,fierce industry competition,and high-quality internal control can strengthen the incentive effect of carbon emissions trading system on firms'green technology innovation.In addition,the incentive effect of carbon emission trading system on firms'green technology innovation is more significant in state-owned firms and firms in areas with limited resource endowments.To sum up,the pilot policy of carbon emission trading system can effectively stimulate firms'green technology innovation,and the incentive effect is quite different among firms in different ownership and resource endowment areas.Based on the conclusions,three suggestions are put forward for improving and effectively implementing China's carbon emission trading system.(1)Market institutions should enrich national carbon emission trading products.(2)Governments should optimize the external environment for carbon emission trading policies.(3)Firms should actively formulate green and low-carbon development strategies.