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Table 4 Unit root analysis.

From: Revisiting the nexus between fiscal decentralization and CO2 emissions in South Africa: fresh policy insights

Variable

Dickey-Fuller GLS

Phillips-Perron

Augmented Dickey-Fuller

Kwiatkowski-Phillips-Schmidt-Shin

Narayan and Pop (2010) Unit Root Test

(DF-GLS)

(PP)

(ADF)

(KPSS)

Model 1

Model 2

Level

Test—Statistics value

Break-Year

ADF-stat

Break-Year

ADF-stat

InCO2

− 0.570

− 0.464

− 1.152

0.966

1982:1985

− 3.132

1987:1994

− 8.160***

InSE

− 0.116**

− 0.079

− 1.308

0.833***

1979:1988

− 2.914

1982:1990

− 7.601***

InTE

− 0.112*

− 0.076

− 1.268

0.848***

1979:1990

− 1.939

1982:1994

− 6.791***

InFISD

− 0.140**

− 0.067

− 1.127

0.692***

1980:1991

− 2.510

2007:2013

− 7.153***

InTECH

− 0.254***

− 0.284***

− 2.999

0.255***

1995:2000

− 4.318

2008:2011

− 7.821***

InEC

− 0.011

− 0.014

− 0.366

1.300***

1982:1989

− 4.372**

1985:1991

− 8.521***

InFDI

− 0.032*

− 0.001

− 0.012

0.640

2001:2006

− 2.021

2004:2010

− 8.362***

InOPEN

− 0.072

− 0.082

− 1.335

1.080*

1996:2001

− 3.053

2003:2009

− 7.318***

InIGDP

− 0.046

− 0.071*

− 1.718

1.060**

1972:1985

− 3.815

1982:1991

− 7.521***

First difference

Critical value (1%, 5%, and 10%)

\(\Delta\)InCO2

− 0.995***

− 0.996***

− 7.176***

0.705***

1999:2005

− 4.801**

1980:1991

− 5.832***

\(\Delta\)InSE

− 0.695***

− 0.707***

− 5.319***

0.585***

1983:1997

− 5.831***

1985:1995

− 6.831***

\(\Delta\)InTE

− 0.694***

− 0.707***

− 5.316***

0.589***

1991:2000

− 8.531***

1987:1996

− 5.893***

\(\Delta\)InFISD

− 0.183***

− 0.485***

− 7.814***

0.602***

1983:1999

− 5.714***

1982:2006

− 5.517***

\(\Delta\)InTECH

− 1.023***

− 1.034***

− 7.473***

0.424***

1999:2003

− 4.841**

2006:2010

− 5.983***

\(\Delta\)InEC

− 1.105***

− 1.121***

− 8.142***

0.586***

1985:1993

− 5.921***

1989:1997

− 7.942***

\(\Delta\)InFDI

− 0.207**

− 0.209**

− 6.443***

0.609***

2005:2008

− 6.831***

2001:2008

− 6.973***

\(\Delta\)InOPEN

− 0.935***

− 0.938***

− 6.699***

0.626***

1996:2004

− 6.842**

2001:2007

− 8.942***

\(\Delta\)InIGDP

− 0.799***

− 0.801***

− 5.878***

0.431***

1975:1990

− 7.742***

1988:1992

− 7.892***

  1. *, ** and *** denote statistical significance at 10%, 5% and 1% levels, respectively. MacKinnon’s (1996) one-sided p-values. Lag Length based on SIC and AIC. Probability-based on Kwiatkowski–Phillips–Schmidt–Shin (1992). The critical values for Narayan-Popp unit root test with two breaks are followed by Narayan and Pop (2010). All the variables are trended