(1)

(2)

(3)

变量

LNFEE

LNFEE

LNFEE

STRADER4

0.232***

0.316***

0.312***

(3.55)

(4.88)

(4.82)

Controls

Yes

Yes

Yes

Constant

4.926***

5.649***

5.652***

(65.36)

(78.94)

(75.97)

Industry fixed effect

Yes

Yes

Yes

Year fixed effect

Yes

Yes

Yes

Observations

18,535

18,535

18,535

R-squared

0.621

0.657

0.657

r2_a

0.620

0.657

0.657