Table 2. Performance of unit root test.
| variable | N-st difference | (C,T,K) | DW | ADF | 5% | 1% | Result |
|---|---|---|---|---|---|---|---|
| TTR | 1 | (C,n,7) | 2.09 | -7.31 | -3.58 | -4.32 | I(1)*** |
| DTR | 1 | (C,n,7) | 2.05 | -5.91 | -3.58 | -4.32 | I(1)*** |
| ITR | 1 | (C,n,7) | 2.19 | -9.35 | -2.97 | -3.68 | I(1)*** |
| GDP | 1 | (C,n,7) | 1.97 | -5.17 | -2.97 | -3.68 | I(1)*** |
Note: (C, T, K) indicates whether the test formula contains constant term, time trend and number of lag periods using AIC. Standard errors in parentheses:
*** denotes the 1st- differenced form passes the stability test at 1% significance level,
** denotes the 1st- differenced form passes the stability test at 5% significance level.