(1)

(2)

(3)

(4)

VARIABLES

COC

COC

COC

COC

RD

−0.000266^**

−0.000529^***

−0.000283^*

−0.000543^***

(−2.021)

(−4.191)

(−1.932)

(−3.867)

SIZE

0.00321^***

0.00313^***

0.00323^***

0.00316^***

(6.785)

(6.862)

(6.647)

(6.747)

AT

0.0108^***

0.00766^***

0.0101^***

0.00729^***

(7.014)

(5.213)

(6.070)

(4.620)

GRO

0.00527^***

0.00526^***

0.00430^***

0.00449^***

(3.494)

(3.602)

(2.855)

(3.088)

ROA

−0.0208^**

−0.0272^***

−0.0190^**

−0.0275^***

(−2.234)

(−3.054)

(−1.982)

(−3.013)

STA

−0.0108^***

−0.0104^***

−0.00945^***

−0.00889^***

(−9.297)

(−9.413)

(−7.921)

(−7.834)

HERF

−0.000290^***

−0.000202^***

−0.000256^***

−0.000173^***

(−7.972)

(−5.797)

(−7.009)

(−4.964)

YTO

−0.00152^***

−3.31e−05

−0.00172^***

−0.000201

(−8.223)

(−0.164)

(−9.218)

(−0.986)

年份效应

No

Yes

No

Yes

行业效应

No

No

Yes

Yes

Constant

0.0453^***

0.0294^***

0.0423^***

0.0267^**

(4.129)

(2.739)

(3.603)

(2.330)

Observations

5606

5606

5606

5606

R-squared

0.059

0.155

0.091

0.186

r2_a

0.0574

0.153

0.0849

0.180

F

43.65

79.00

15.86

31.70