Table 1.
Estimates of unit root test
| Variables | Level | First difference | ||
|---|---|---|---|---|
| Constant | Constant + Trend | Constant | Constant + Trend | |
| CO2 | − 0.534 (0.873) | − 1.807 (0.681) | − 4.481 (0.001) | − 4.332 (0.007) |
| FR | − 5.205 (0.000) | − 1.307 (0.851) | − 1.440 (0.551) | − 5.048 (0.001) |
| COMDIS | − 0.402 (0.898) | − 2.401 (0.373) | − 6.337 (0.000) | − 6.306 (0.000) |
| ECR | 1.395 (0.998) | − 2.403 (0.372) | − 4.819 (0.000) | − 4.392 (0.001) |
| EPC | − 0.723 (0.828) | − 1.881 (0.645) | − 5.637 (0.000) | − 5.619 (0;000) |
| FPI | − 0.397 (0.899) | − 1.130 (0.910) | − 4.572 (0.000) | − 4.505 (0.004) |
| FPRICE | − 2.440 (0.136) | − 3.454 (0.058) | − 5.902(0.000) | − 5.894 (0.000) |
| KSO | − 2.699 (0.083) | − 3.626 (0.041) | − 5.774(0.000) | − 5.418 (0.000) |
| PDEN | − 1.882 (0.336) | − 0.199 (0.990) | − 0.506 (0.879) | − 0.770 (0.959) |
| POVHCRa | 0.947 (0.995) | − 1.424 (0.837) | − 6.439 (0.000) | − 7.136 (0.000) |
| VEMP | − 3.364 (0.019) | − 1.778 (0.695) | − 2.030 (0.273) | − 2.493 (0.325) |
aPhillips Perron unit root estimates. Small bracket shows probability values