(9)

(10)

(11)

(12)

变量滞后检验

2SLS检验

替换被解释变量

第一阶段

第二阶段

Innovation

Innovation

Innovation

Innovation

DF

0.009^***

0.195^*

(7.10)

(1.94)

L.DF

0.006^*

(1.94)

Internet

3.122^***

(48.77)

Size

−0.000

0.114^***

−0.005^***

0.363^***

(−0.07)

(21.90)

(−13.90)

(17.65)

Lev

−0.009^***

−0.296^***

−0.038^***

−0.132^*

(−4.02)

(−9.03)

(−18.65)

(−1.75)

Ownership

−0.010^***

−0.732^***

−0.024^***

−0.193

(−2.87)

(−19.70)

(−9.42)

(−1.57)

Indep

−0.014^**

0.116

0.035^***

−0.597^***

(−2.53)

(0.19)

(5.84)

(−3.12)

Dual

0.000

−0.028^**

0.006^***

−0.027

(0.48)

(−2.24)

(7.40)

(−1.23)

Fixed

0.013^***

−0.008

−0.047^***

0.395^***

(4.12)

(−0.21)

(−20.67)

(3.74)

Audit

0.004^***

0.229^***

0.005^**

0.092^*

(3.31)

(6.21)

(2.10)

(1.92)

Roa

−0.020^***

−0.083^***

−0.025^***

−0.060

(−18.12)

(−6.09)

(−29.37)

(−1.58)

Growth

−0.008^***

−0.152^***

−0.001

−0.005

(−15.63)

(−10.15)

(−1.40)

(−0.28)

Is

−0.015

−0.214^***

−0.029^***

2.357^***

(−1.10)

(−3.29)

(−7.12)

(5.24)

Pgdp

0.005

0.494^***

−0.006^***

0.275

(0.73)

(23.19)

(−3.23)

(1.19)

常数项

−0.006

−6.914^***

0.243^***

−10.859^***

(−0.07)

(−27.96)

(11.51)

(−4.32)

时间效应

YES

YES

YES

YES

个体效应

YES

YES

YES

YES

F

60.870^***

1466.12^***

106.37^***

Within_R²

0.102

0.554

0.247

0.152

Wald检验

4788.62^***

样本量

12438

14199

14199

14199