Variables | Test ADF (trend + constant) | Test PP (trend + constant) | Test KPSS (trend + constant) | |
Level | First Difference | Level | Level | |
PCR | −3.597* | −3.597* | 0.739* | |
Investment | −3.597* | −3.601* | 0.739* | |
Opex | −4.205* | −4.192* | 0.739* | |
Salary | −2.607*** | −2.621* | 0.739* |