Analysis of Causality Test Based on Error-Correction Model
Having found that there is a long-run relationship between OILP and y/N, the next step is to test for the causality
between the variables used by incorporating the lagged error-correction term into equations (3 and 4). The causality
in this case is examined through the significance of the coefficient of the lagged error-correction term and joint
significance of the lagged differences of the explanatory variables using the Wald test. The results of the Grangercausality
test are reported in Table 5.