Figure 2
A line graph titled CUSUM stability test. The x axis represents observations ranging from 0 to 100. The y axis represents the CUSUM of recursive residuals ranging from -1.25 to 0.50. The blue line represents the CUSUM values, which fluctuate across the observations. Two red dashed lines indicate the 5 percentage significance bands at approximately 0.50 and -0.50. The CUSUM line crosses below the lower significance band around observation 30 and remains mostly below it thereafter. All values are approximated.CUSUM stability test. Source: Author's computation based on Prais–Winsten regression results, 2015–2022 data