Table 2.

Results of unit root test

Variable	Level	Prob. values	1stdifference	Prob. values	Order of integration
	Constant		Constant
RER	−1.5	0.51	−3.10	0.040	I(1)
PROD	−2.04	0.20	−7.11	0.000	I(1)
TOT	−1.9	0.30	−5.64	0.000	I(1)
TO	−2.42	0.14	−7.22	0.000	I(1)
GEX	−1.41	0.55	−5.98	0.000	I(1)

Note: The null hypothesis is that the series is non-stationary, or contains a unit root. The rejection of the null hypothesis is based on MacKinnon (1996) critical values i.e., at constant: -3.646, -2.954 and −2.615 are significant at 1%, 5% and 10% level respectively. The lag length are selected based on SIC criteria, this ranges from lag zero to lag four.