3.2.1. Dependent Variable

Green innovation. The number of patents is an essential indicator of the green innovation level of an enterprise. As reported by Ko et al. (2021) [73], we applied the natural logarithm of the sum of the total number of applications of green innovation patents and utility patents plus 1 to measure corporate green innovation (GRInno). We classified the application of green invention patents as exploratory green innovation (GRInva) and the application of utility patents as exploitative green innovation (GRUma). Furthermore, we employed various green innovation patent applications as the dependent variable (corporate green innovation) for the robustness test to promote the reliability of the research results.
