variant

Test Type

（c, t, p）

ADF statistic

1% critical value

5% critical value

10% critical value

Result

LnDS

(c, t, 4)

−2.29

−3.83

−3.03

−2.66

Non-stationary

LnFDI

(c, t, 4)

−1.118

−3.83

−3.03

−2.66

Non-stationary

LnGDP

(c, t, 4)

1.05

−3.96

−3.08

−2.68

Non-stationary

LnTAX

(c, t, 4)

−0.22

−3.83

−3.03

−2.66

Non-stationary

D LnDS

(c, 0, 4)

−4.32^*

−3.86

−3.04

−2.66

Stationary

D LnFDI

(c, 0, 4)

−5.24^*

−3.86

−3.04

−2.66

Stationary

D LnGDP

(c, 0, 4)

−2.76^***

−4.00

−3.01

−2.69

Stationary

D LnTAX

(c, 0, 4)

−3.49^**

−3.92

−3.07

−2.67

Stationary