- ‘***’, ‘**’ and ‘*’ denote significance at the 1%, 5%, and 10% level respectively. The 1%, 5% and 10% critical values are − 4.15, −3.50 and − 3.18 respectively for ADF; 3.96, 5.62, and 6.89 respectively for PT and − 3.48, −2.89, and − 2.57 for GLS of DF-GLS test; 0.216, 0.146 and 0.119 respectively for KPSS; and − 4.084, − 3.487 and − 3.1850 respectively for LS crash model and − 4.907, −4.345 and − 4.068 respectively for break model. The variables are in natural logarithm form. D stands for break in the intercept and DT break in the slope
