(a)

(b)

(c)

(d)

dlInvention

lInvention

lInvention

lInvention

L.inde_com

0.795***

0.395

0.395

0.395

(3.08)

(1.46)

(1.08)

(0.87)

L.log_Total

0.515***

0.400***

0.400***

0.404***

(29.97)

(12.88)

(6.47)

(6.28)

L.cap_exp

0.671***

0.359*

0.359

0.356

(2.85)

(1.68)

(1.31)

(1.01)

L.Leverage

−0.000203*

0.000619

0.000619***

0.000689***

(−1.70)

(1.34)

(6.11)

(10.55)

L.Borad_size

0.0432***

0.0212**

0.0212

0.0334*

(5.04)

(2.11)

(1.26)

(1.88)

L.logQ

0.0747***

0.0225***

0.0225***

0.0185*

(4.35)

(3.01)

(2.99)

(1.89)

year_pre2003

−0.000396**

−0.000385**

(−2.26)

(−2.25)

_cons

−11.48***

−8.895***

−8.104***

−8.304***

(−23.40)

(−12.78)

(−5.97)

(−5.90)

N

8185

8185

8185

8185

r2

0.218

0.219

0.219

0.220

Year fixed effects

Yes

Yes

Yes

Yes

Firm fixed effects

No

Yes

Yes

Yes

Trend control

No

No

Yes

Yes

Control*bill

No

No

No

Yes