*3.3. Robustness Test*

## 3.3.1. Replace Dependent Variables

This study replaced the quantitative index of technological innovation with the number of patent applications provided by the CNRDS database (*cpt*, *cpi*, *cpu*). The patent quality index was replaced by the number of cited patents (*cited*) and patent claims (*claim*). The regression results are presented in Table 6. It can be seen that after replacing the measurement indicators, the regression results are consistent with the benchmark regression results.

**Table 6.** Robustness test: Replace the dependent variables.


Note: Robust standard errors are given in parentheses. \* *p* < 0.1, \*\* *p* < 0.05, \*\*\* *p* < 0.01. CONTROLS includes capital structure (*lev*), profitability (*roa*), enterprise size (*size*), proportion of fixed assets (*ppe*), proportion of independent directors (*dir*), enterprise age (*age*), enterprise growth ability (*gov*), and human capital (*hc*).

#### 3.3.2. Subsample Regression

Considering that some enterprises may enter the new energy vehicle industry in a certain period, this paper verified the time when each enterprise entered the industry by consulting the annual report of the enterprise, and then selected the sub-sample after the enterprise entered the new energy vehicle industry for regression. The regression results are shown in Table 7. We can see that the regression results are consistent with the benchmark regression results.



Note: Robust standard errors are given in parentheses. \* *p* < 0.1, \*\* *p* < 0.05, \*\*\* *p* < 0.01. CONTROLS includes capital structure (*lev*), profitability (*roa*), enterprise size (*size*), proportion of fixed assets (*ppe*), proportion of independent directors (*dir*), enterprise age (*age*), enterprise growth ability (*gov*), and human capital (*hc*).
