Table 1 Breakpoint unit root test... | Emerald Publishing

Table 1

Breakpoint unit root test

	Intercept (t statistic)		Intercept and trend (t statistic)
	Level	1st difference	Level	1st difference
CO₂	−1.28	−7.06***	−6.37***
GDP	1.45	−5.41***	−3.35	−6.64***
GDP²	4.32*		−2.16	−7.97***
GDP³	−1.97	−3.82	−3.68	−7.65***
Oil price	−3.15	−7.36***	−4.69**
Petroleum consumption	−1.38	−6.34***	−2.94	−6.65***
Trade openness	−1.36	−6.93***	−5.47***
FDI	−3.53	−6.75***	−3.52	−6.85***
Size of government	−5.90***		−6.84***

	Intercept (t statistic)		Intercept and trend (t statistic)
	Level	1st difference	Level	1st difference
CO₂	−1.28	−7.06***	−6.37***
GDP	1.45	−5.41***	−3.35	−6.64***
GDP²	4.32*		−2.16	−7.97***
GDP³	−1.97	−3.82	−3.68	−7.65***
Oil price	−3.15	−7.36***	−4.69**
Petroleum consumption	−1.38	−6.34***	−2.94	−6.65***
Trade openness	−1.36	−6.93***	−5.47***
FDI	−3.53	−6.75***	−3.52	−6.85***
Size of government	−5.90***		−6.84***

Note(s): ***, ** and * denote level of significance at 1, 5 and 10%, respectively