$\Delta D_{it}=\alpha +\beta DE{F}_{it}+{\epsilon }_{it}$

sample 1 (1)

sample 2 (2)

β

0.114128****

(0.0070)

0.149526**

(0.0123)

N

99

99

R²

0.102778

0.131678

F-test

7.331285***

9.093747**