{
  "name": "Forecast Accuracy Ledger: How Our Manufacturing Forecasts Have Actually Done",
  "slug": "us-manufacturing-forecast-accuracy",
  "version": "1.0.0",
  "url": "https://www.mfgcalcs.com/signals/forecast-accuracy",
  "formula": "Every published forecast carries a walk-forward backtest: one-step-ahead predictions made on data the model had not seen, versus the actual that arrived. This ledger aggregates all of those points: observation-level absolute percentage error (median, mean, 90th percentile); the share of predictions within 5% and 10% of actual; the directional hit rate (did the model call the sign of the next move); the median error by category; and the most- and least-accurate series by backtest error.",
  "unit": "absolute percentage error; hit rates in percent.",
  "scope": "ONE-STEP-AHEAD out-of-sample accuracy — the model's short-horizon calibration. The published forecasts run six months out and error compounds with horizon, so read this as how well the next step is called, not the six-month number.",
  "source": "MFG Calcs deterministic forecaster (damped Holt-Winters) walk-forward backtests over U.S. federal open data and derived tariff Signals.",
  "provenance": "Self-graded from the same committed backtests the per-forecast pages render. Redistributable.",
  "license": "https://creativecommons.org/licenses/by/4.0/",
  "attribution": "MFG Calcs (mfgcalcs.com)",
  "asOf": "2026-07"
}