变量

(1)

(2)

(3)

dif

0.033^**

(2.19)

0.065^***

(4.08)

−0.585^***

(−2.96)

inno

−0.009^***

(−5.51)

dif^*inno

0.061^***

(6.43)

fd

0.137^***

(3.14)

dif^*fd

−0.651^***

(−2.67)

gov

−0.010^*

(−1.66)

−0.009

(−1.53)

−0.008

(−1.15)

is

0.078^***

(4.62)

0.032^***

(4.21)

0.033^***

(4.15)

gdp

0.058^***

(2.93)

0.074^***

(4.56)

0.092^***

(5.24)

open

0.031^***

(3.83)

0.047^**

(2.49)

0.079^***

(3.79)

时间效应

Yes

Yes

Yes

地区效应

Yes

Yes

Yes

N

330

330

330

R²

0.660

0.114

0.491