变量

(1)

(2)

(3)

D

0.442^**

0.563^***

0.571^***

(2.32)

(3.612)

(3.331)

Inv

0.019

0.038^**

0.039^*

(0.766)

(2.001)

(1.821)

lnCoop

0.198^***

0.217^***

0.217^***

(8.999)

(7.408)

(7.389)

lnStr

−0.038

−0.246^**

−0.244^**

(−0.268)

(−2.111)

(−2.054)

lnEr

−0.013

−0.028^*

−0.027^*

(−0.635)

(−1.802)

(−1.762)

lnpopu

−0.039

−0.039

(−0.91)

(−0.917)

lnpgdp

−0.006

(−0.112)