The massive emission of greenhouse gases poses a serious threat to the ecological environment. In this context, the relevant effects of the carbon emission trading (CET) market, which promotes greenhouse gas emission reduction by market means, have been widely investigated. Taking the China's CET pilot as a research target, the heterogeneity and spillover effects of CET on green innovation are explored by using the sample data of 279 prefecture-level cities in China from 2008 to 2019. The results are as follows. First, on the whole, CET significantly promotes strategic green innovation, but it has no significant effect on substantive green innovation. Second, the green innovation effect of CET varies with the level of green innovation, and the heterogeneous effects of green innovation are also reflected in different degrees of marketization, fiscal decentralization and government environmental concern. Third, CET has a positive spillover effect on green innovation, and the spillover effect is more significant than the direct effect, accounting for 74.8% of the total effect. Finally, some corresponding policy suggestions are put forward according to the above research conclusions.
Keywords: carbon emission trading; green innovation; heterogeneity effects; spillover effects.