Emissions trading schemes (ETS) area is a leading climate policy instrument worldwide and have been widely discussed and researched. However, few studies to date focus on the nexus of ETS and income inequality, an important socioeconomic phenomenon. To fill this gap, taking China as an example, this paper discusses the influence of ETS on income inequality and its dynamic changes using a time-varying differences-in-difference model combined with a propensity score matching approach. The results demonstrate that China's pilot ETS has contributed to reducing income inequality. Various robustness tests support this conclusion. Moreover, the strength of ETS's contribution to reduction in income inequality gradually increases over time. We further analyze the mediating effects of carbon intensity, energy consumption, industrial structure, and technological innovation. ETS reduces income inequality by reducing coal consumption. The regional heterogeneity analysis shows that, unlike in other regions, ETS has a positive impact on income inequality (i.e. it increases it) in the eastern region in China due to its optimized energy structure and relatively complete, open, and flexible economy system. The paper discusses the above findings and their policy implications. It is also designed to promote research on ETS and to diversify research perspectives of income inequality from both theoretical and practical aspects. Key policy insights Evidence from China's pilot experience with ETS shows that it contributes significantly to balancing income distribution and alleviating the increasingly acute social conflicts caused by income inequality. This provides new theoretical and decision support for the promotion of ETS in the future. The energy revolution driven by ETS promotes income redistribution, which is conducive to income equality. Governments should enforce the constraints of ETS on power generation companies; guide capital to invest more in the non-thermal power industry, especially the renewable energy power sectors; and guide and regulate the income distribution in new power sectors. Governments' revenue from ETS can and should be used to further redistribution of income and to reduce income inequality. A higher number of free quotas and a lower carbon price could be imposed on low-profit or labor-intensive industries to reduce their emission costs.
