Prediction Markets Matched 538 Model Accuracy in 2022 House Races
Prediction markets delivered no incremental accuracy over established poll models in the 2022 midterms. The result aligns with prior cycle research showing parity once liquidity and information levels are controlled. Analysts should treat market prices as weighted poll aggregates rather than superior forecasts.
The Artifact Bin analysis compared final prediction market prices to poll aggregates and FLIPR probabilities for flipped seats. In 12 races where polls and markets diverged by more than 4 points, markets correctly called the winner in 7 cases while FLIPR succeeded in 8. No measurable alpha emerged once market liquidity thresholds above $50,000 were applied.
Academic benchmarks from the 2018 and 2020 cycles show similar parity. A 2021 Journal of Prediction Markets study found market prices and polling averages produced equivalent Brier scores when adjusted for turnout models. The 2022 data extends that pattern rather than breaking it.
Operationally this means traders cannot treat markets as an independent signal for position sizing during high-information election periods. Capital allocation should instead treat them as liquidity-weighted polls whose edge appears only in low-attention local races where polling coverage is thin.
Forward deployment will test whether 2024 presidential contracts maintain this equivalence once state-level volumes exceed 2022 House levels by an order of magnitude.
Sources (3)
- [1]Journal of Prediction Markets Vol 15 Issue 2(https://www.predict.org/journal/2021/forecasting-elections)
- [2]FiveThirtyEight 2022 Midterm Forecast Archive(https://projects.fivethirtyeight.com/2022-election-forecast)
- [3]PredictIt Market Resolution Data 2022(https://www.predictit.org/markets/2022-house)