The Limits of Prediction
Why perfect election prediction is impossible, what uncertainty teaches us about democracy, and how to live with not knowing the outcome.
Why We Cannot Know the Future
Election prediction faces irreducible uncertainty for several reasons. Human behavior is not deterministic: voters change their minds, respond to late-breaking events, and sometimes act unpredictably. Turnout is partly random: rain, transportation problems, and personal emergencies affect who votes. Small polling errors in close races produce incorrect outcome predictions even when the polls are within their normal accuracy range.
The political scientist Philip Tetlock, who has spent decades studying prediction, found that experts are only marginally better than chance at forecasting political events more than a few months out. The world is simply too complex and contingent for precise prediction. A candidate's heart attack, a financial crisis, a pandemic, or a foreign policy crisis can reshape an election overnight in ways no model can anticipate.