CH₄ Stationarity

Variable

Intercept

Trend &

Intercept

Intercept

Trend & Intercept

Order of integration

ADF I(1)

ADF I(1)

PP I(1)

PP I(1)

L(CH₄)

−8.176*

−8.110*

−8.971*

−8.971*

I(1)

L(GDPP)

−6.149*

−6.129*

−6.129*

−6.129*

I(1)

L(GDPP)²

−6.006*

−6.056*

−6.056*

−6.056*

I(1)

L(EUP)

−8.887*

−9.501*

−9.510*

−9.510*

I(1)

L(OIL)

−5.496*

−5.595*

−5.578*

−5.578*

I(1)

L(CPIN)

−10.295*

−10.188*

−10.546*

−10.546*

I(1)

L(TOP)

−8.381*

−8.284*

−8.171*

−8.171*

I(1)

L(FDI)

−7.266*

−7.190*

−25.252*

−25.252*

I(1)

N₂O Stationarity

Intercept

Trend &

Intercept

Intercept

Trend & Intercept

Order of integration

ADF I(1)

ADF I(1)

PP I(1)

PP I(1)

L(N₂O)

−7.443*

−7.528*

−7.443*

−7.535*

I(1)

L(GDPP)

−6.149*

−6.129*

−6.149*

−6.129*

I(1)

L(GDPP)^2

−6.006*

−6.056*

−6.004*

−6.056*

I(1)

L(EUP)

−8.887*

−9.501*

−9.046*

−9.501*

I(1)

L(OIL)

−5.496*

−5.595*

−5.482*

−5.578*

I(1)

L(CPIN)

−10.295*

−10.188*

−10.659*

−10.546*

I(1)

L(TOP)

−8.381*

−8.284*

−8.260*

−8.171*

I(1)

L(FDI)

−7.266*

−7.190*

−22.946*

−25.252*

I(1)