Do green technology innovations contribute to carbon dioxide emission reduction? Empirical evidence from patent data

This paper investigates the impact of green technology innovations on carbon dioxide (CO2) emissions based on a data panel covering 71 economies from 1996 to 2012. Specifically, we examine whether the level of income matters for the effect of green technology innovations. It is found that the impact of green technology innovations exists a single threshold effect regarding the income level. Specifically, green technology innovations do not significantly contribute to reducing CO2 emissions for the economies whose income levels are below the threshold while the mitigation effect becomes significant for those whose income levels surpass the threshold. But the transition of regime occurs at an extremely high-income level. In addition, we find that the relationship between per capita CO2 emissions and per capita GDP is inverted U-shaped, and urbanization level, industrial structure, trade openness, and energy consumption structure also significantly affect CO2 emissions. Finally, this paper suggests that mechanism innovations should be implemented to reduce the diffusion cost of green technology in undeveloped economies.