The impact of China’s SO2 emission trading system on industrial total factor productivity: evidence from industrial sub-sectors at the provincial level

Much attention has been devoted to the economic benefits of emission trading systems (ETSs), but research concerning the SO2 ETS in China is scarce. We examine China's SO2 ETS in 2007 from the perspective of industrial sub-sectors and employ the difference-in-difference-in-difference (DDD) model to test whether the SO2 ETS can promote industrial total factor productivity (TFP). We identify whether it is the average effect or the dynamic effect of the SO2 ETS that can improve industrial TFP. The heterogeneity test results indicate that this policy has diverse influence in different regions and industries, and the effect is better in pollution-intensive industries. We also find that the policy enhances industrial TFP by promoting efficient technological innovation and capital allocation. Our findings provide evidence that supports the Porter Hypothesis and a guide for the industrialization of developing countries. Chinese policymakers should strengthen environmental enforcement, set quotas accordingly, and encourage technological innovation to improve industrial TFP.