The main reason why financial and time series intrinsically exhibit some form of nonstationarity is that:
A) |
serial correlation, a contributing factor to nonstationarity, is always present to a certain degree in most financial and time series. | |
B) |
most financial and time series have a natural tendency to revert toward their means. | |
C) |
most financial and economic relationships are dynamic and the estimated regression coefficients can vary greatly between periods. | |
Because all financial and time series relationships are dynamic, regression coefficients can vary widely from period to period. Therefore, financial and time series will always exhibit some amount of instability or nonstationarity. |