Business confidence as a strong tracker of future growth: is it driven by economic policy uncertainty and oil price shocks in the OECD countries?

Future Business Journal

Table 3 Unit root tests results

Variables	Full sample	Sub-sample		Full sample	Sub-sample
		Eurozone	Non-Eurozone		Eurozone	Non-Eurozone
	CIPS			CADF
\(bci\)	−2.635^a,***	−2.108^a,***	−2.635^a,***	−5.020^a,***	−4.826^a,***	−5.511^a,***
\(int\)	−6.420^b,***	−3.571^a,***	−2.424^a,**	−3.436^a,***	−3.210^a,***	−2.263^a,**
\(unm\)	−6.420^b,***	−6.190^b,***	−2.525^a,***	−6.152^b,***	−6.036^a,***	−6.343^a,***
Global (cross-section invariant) series (2000M1–2020M03)
	PP		DFGLS		ADF−SB
\(brent\)	−11.017^b,***		−8.745^b,***		−12.457^b,***
\(WTI\)	−10.089^b,***		−6.002^b,***		−11.673^b,***
\(epu\)	−4.6207^a,***		−4.8178^b,***		−6.4700^b,***

The stationarity feature of the global series (Brent, WTI and epu) is conducted with time series unit root tests since they are cross-section invariant. a and b, respectively, denote level and first difference stationarities. *** and ** denote significance at 1% and 5% critical levels