Table 2.

Panel unit root tests.

ADF	t-statistics	p-value	t-statistics	p-value
lnCO2	−0.5959	0.8628	−5.4315	0.0000***
lnFD	0.7289	0.9918	−4.7688	0.0003***
lnGDP	1.8768	0.9998	−3.8884	0.0039***
lnPOP	−3.3610	0.0170**	−0.8979	0.7815
LnREE	−2.7721	0.0689*	−5.8710	0.0000***
lnTO	−1.1549	0.6876	−5.1780	0.0001***

***, **, and * shows the level of significance at 1%, 5%, and 10%.