Table 2.

Panel unit root test with cross-sectional dependency results

Variable	Level		1st difference		Order of integration
	Intercept	Intercept and trend	Intercept	Intercept and trend
Pesaran CADF test
lnREC	− 1.488	− 2.429	− 2.519***	− 3.220**	I(1)
lnRES	− 1.116	− .1717	− 0.453	− 3.204**	I(1)
lnRELEC	− 1.823	− 2.511	− 3.133***	− 3.072**	I(1)
lnROILP2/lnROILP2	− 1.610	− 1.700	− 2.819***	− 3.700***	I(1)
lnRGDP	− 1.691	− 2.222	− 2.281	− 3.979***	I(1)
lnROILP * lnRGDP	− 1.283	− 1.586	− 2.456*	− 3.998***	I(1)
lnDEPEND	− 1.919	− 2.283	− 3.892***	− 3.794***	I(1)
lnCO2	− 1.849	− 2.721	− 3.216***	− 3.209**	I(1)
lnTO	− 1.969	− 1.806	− 2.435*	− 3.983***	I(1)
Pesaran CIPS test
lnREC	− 2.001	− 2.129	− 6.001***	− 6.084***	I(1)
lnRES	− 2.068	− 1.954	− 4.945***	− 5.023***	I(1)
lnRELEC	− 2.101	− 2.023	− 5.682***	− 5.678***	I(1)
lnROILP2/lnROILP2	− 1.610	− 1.700	− 3.320***	− 3.952***	I(1)
lnRGDP	− 1.677	− 2.113	− 4.417***	− 4.389***	I(1)
lnROILP * lnRGDP	− 0.552	− 1.895	− 3.709***	− 3.764***	I(1)
lnDEPEND	− 1.995	− 1.942	− 5.183***	− 5.165***	I(1)
lnCO2	− 2.139	− 2.019	− 5.445***	− 5.541***	I(1)
lnTO	− 1.615	− 1.849	− 5.295***	− 5.288***	I(1)

The optimal lags are chosen based on the akaike information criterion (AIC)

***, **, *Statistical significance at 1%, 5% and 10% levels, respectively