Level Values First Difference | |||||
Variables | Constant | Constant & Trend | Constant | Constant & Trend | Order of Integration |
lnEXCt | −3.070** (0.038) | −1.852 (0.656) | -------------------- | ------------------- | I (0) |
lnCOPt | −1.083 (0.711) | −2.277 (0.434) | −5.562*** (0.000) | −5.494*** (0.000) | I (1) |
lnOREVt | −1.665 (0.439) | −0.662 (0.968) | −5.968*** (0.000) | −5.363*** (0.000) | I (1) |
lnGDPCt | 0.046 (0.956) | −1.516 (0.803) | −5.126*** (0.000) | −4.827*** (0.002) | I (1) |