Figure 3
A line graph titled CUSUM of Squares CUSUMSQ Stability Test. The x axis represents Time in Months from 0 to 100, labeled as 2015 to 2022. The y axis represents the CUSUMSQ Statistic ranging from negative 0.6 to positive 0.6. The graph features a solid blue line representing the CUSUMSQ statistic and a dashed red line representing the 5 percentage significance bounds. The blue line starts at approximately 0.2, fluctuates slightly, and remains relatively stable around 0.2 throughout the time period. The red dashed lines form upper and lower bounds, starting at approximately negative 0.6 and positive 0.6, and gradually diverging slightly over time. All values are approximated.CUSUMSQ stability test. Source: Author's computation based on Prais–Winsten regression results, 2015–2022 data