Variable

Level of test

t-statistics (ADF test )

Conclusion of ADF test (5% level)

t-statistics (Phillips -Perron test)

Conclusion of Phillips-Perron test

DEBT

Level

4.24

unit root

3.51

unit root

First difference

−3.32

No unit root (10%)

−6.06

No unit root

GDP

Level

1.45

unit root

1.49

unit root

First difference

−8.02

No unit root

−8.02

No unit root

NDWELL

Level

−1.72

unit root

−1.95

unit root

First difference

−4.82

No unit root

−4.78

No unit root

HPI

Level

−1.72

unit root

−1.95

unit root

First difference

−4.82

No unit root

−4.78

No unit root

R

Level

−2.32

unit root

−1.67

unit root

First difference

−3.99

No unit root

−3.96

No unit root

ER

Level

−1.18

unit root

−1.24

unit root

First difference

−4.60

No unit root

−7.44

No unit root

U

Level

−3.81

unit root

−1.75

unit root

First difference

−2.47

No unit root

−3.85

No unit root

NX

Level

−1.79

unit root

−0.84

unit root

First difference

−3.16

No unit root

−7.85

No unit root

CPI

Level

−1.70

unit root

−2.24

unit root

First difference

−6.37

No unit root

−6.65

No unit root

POP

Level

−0.59

unit root

−0.65

unit root

First difference

−3.11

No unit root (10%)

−8.53

unit root