Summary of Revenue Forecast Uncertainty for the Current Biennium
In Minnesota’s November 2024 Budget and Economic Forecast, total revenues for FY 2024-25 are forecast to be $61.434 billion. This forecast was constructed eight months before the current biennium closes. If this forecast turns out to have the same degree of accuracy as the average of our eight-months-ahead forecasts, we can expect FY 2024-25 closing revenues to be between $60.474 and $62.394 billion (+/- $960 million).
Total revenues for FY 2026-27 are forecast to be $63.853 billion. This forecast was constructed 32 months before the close of the biennium. If this forecast is consistent with average accuracy of our 32-months-ahead forecasts, we can expect FY 2026-27 closing revenues to be between $59.763 and $67.943 billion (+/-$4.09 billion).
Estimating Revenue Forecast Uncertainty
The difference between the level of revenues forecast and the amount actually collected at the end of a biennium—the forecast error—is a gauge of forecast accuracy. The mean absolute error (MAE) is the average of the errors’ absolute values (that is, treating negative and positive errors the same). Since accuracy in forecasting a single biennium’s revenues improves the closer we get to the end of the two-year period, we calculate separate errors for each time a biennium is part of the forecast: 32, 29, 20, 17, 8 and 5 months from actual. We then average those errors over FY 1990-91 to the most recent closed period, FY 2022-23. This report is the first to incorporate forecast errors calculated for the FY 2022-23 biennium.
