| Abstract: | Forecasting state general fund revenue (GFR) though business cycles means possibly confusing a cycle with an underlying long‐run trend. Relative to the actual revenue, the mean squared error of the academic, legislative, governor's, the growth path (GP), and Holt‐Winters (HW) forecasts for Idaho GFR was not significantly different than the naïve forecast's; the Combined GP‐HW forecast has significantly smaller mean square error. The GP model (ARIMA 1, 2, 1) produced a short‐run elasticity of revenue with respect to income of 1.05 (±0.05). The best GFR forecasts combined a HW two‐step‐ahead level with a GP one‐step‐ahead trend that provided a forecast of GFR with the smallest root mean square error between FY 1998 and FY 2009. A budget stabilization fund needs to be 34–40 percent of GFR for GFR to sustain growth at the state's long‐run expansion rate during a contraction. |
