*4.1. Mechanism Test*

In order to empirically test the mechanism of government subsidies affecting the amount of technological innovation of new energy vehicle enterprises, this paper designed the following mechanism test econometric models:

$$atten\_{it} = \beta\_0 + \beta\_1 sub\_{it} + \beta\_2 X\_{it} + firm\_i + year\_t + \varepsilon\_{it} \tag{3}$$

$$R \& D\_{it} = \beta\_0 + \beta\_1 sub\_{it} + \beta\_2 X\_{it} + firm\_i + year\_t + \varepsilon\_{it} \tag{4}$$

$$fund\_{it} = \beta\_0 + \beta\_1 sub\_{it} + \beta\_2 X\_{it} + firm\_i + year\_t + \varepsilon\_{it} \tag{5}$$

where *attention* represents the degree of external attention of an enterprise; *R*&*D* represents an enterprise's R&D capital investments; *f und* represents the external financing of an enterprise. The other symbols have the same meaning as in Models (1) and (2).

In this paper, the logarithm of the number of analysts who make profit forecasts for enterprises every year was taken as the proxy variable that enterprises are concerned by the outside world [38]. The logarithm of an enterprise's annual R&D expenditure was used to measure *R*&*D*. *f und* was measured by the ratio of net cash flow from financing activities to total assets [39].

#### 4.1.1. Improving the External Attention of Enterprises

Table 10 presents the regression results of the mechanistic tests. It can be seen from column (1) that government subsidies can significantly improve the number of analysts who pay attention to the subsidized enterprises. The more government subsidies the enterprises receive, the more attention they will receive from the outside world, which will increase the possibility of enterprises integrating various external innovation resources [38]. Therefore, government subsidies can promote technological innovation by increasing the attention of the enterprises.


**Table 10.** Mechanism test.

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*).
