variable

Patent

R & D

b2

0.0401

0.0006

(−0.36)

(−0.3)

b1

0.0362

0.001

(−0.35)

(−0.37)

treat

0.2493**

0.0049*

(−2.21)

(−1.82)

a1

0.2311**

0.0036**

(−2.46)

(−2.05)

a2

0.2922**

0.0049**

(−2.05)

(−2.03)

a3

0.2673**

0.0071**

(−1.98)

(−2.67)

X

control

control

year

Yes

Yes

individual

Yes

Yes