Perhaps, one of the most boring economic variables to forecast is the annual average interest rate. Why? Because there is no need for sophistication in the needed mathematics and no challenge of any sort in terms of economic modeling. Consider the 91-day Treasury bill (T-bill), the interest rate on which is the one that most, if not all, market-determined rates go with. What would be the best forecast for next year? Simply look at the newspaper and look at its current rate, and there you have it. The best forecast of the future interest rate is the present one.