Figure 6.
The upper graph shows the C U S U M test values between 2012 and 2022, with the plotted line remaining within the upper and lower bounds, suggesting model stability. The lower graph presents the C U S U M of squares test for the same period, where the cumulative line increases steadily but stays within confidence limits. Together, these plots indicate that the estimated regression model maintains parameter stability and consistency over the observed years, verifying that structural changes in the model are not statistically significant.Charts of CUSUM and CUSUM of Squares tests
Source: Authors’ generated by using the EViews software