Forecasting Geopolitical Events — What Works, What Doesn't (the Tetlock Framework)
Calibrated probabilities, base rates, the Good Judgment Project, and the discipline that distinguishes forecasting from punditry
Between approximately 2011 and 2015, a research project sponsored by the Intelligence Advanced Research Projects Activity (IARPA) — the U.S. intelligence community's research-and-development organization — ran one of the largest controlled forecasting tournaments in history.
The Good Judgment Project, led by Philip Tetlock and Barbara Mellers at the University of Pennsylvania, recruited thousands of volunteer forecasters, asked them to assign calibrated probabilities to specific geopolitical questions over multi-month time horizons, scored their performance using Brier scores (a standard measure of probability-forecasting accuracy), and identified a small subset of consistently top-performing forecasters whom the project termed 'superforecasters.' The cumulative findings — documented in Tetlock and Gardner's Superforecasting: The Art and Science of Prediction (Crown, 2015) and in the underlying academic literature — were that careful forecasting practice substantially outperformed unstructured intuition, that top-performing volunteer forecasters substantially outperformed broader populations, and that in some categories the top volunteer forecasters performed comparably to or better than U.S.
intelligence community analysts with classified-information access.
That is the opening. Finishing a lesson is where it stops being interesting and starts being useful: the full lesson runs to 7 sections and ends with 6 practice questions. A free account is what opens the rest, and the other 255 lessons in the Academy with it. No card.
What this lesson covers
- 1Base rates — why the historical reference class matters
- 2Why pundit-style commentary fails the calibration test
- 3The Brier score and what it actually measures
- 4The forecasting discipline at a glance — Tetlock framework practices
- 5What the Good Judgment Project actually demonstrated — empirical results 2011-2015
- 6Where to see this on the platform
- 7Summary