Key takeaway: Empirical research and historical outcomes demonstrate that prediction markets consistently deliver superior accuracy compared to traditional polling when forecasting elections and significant developments. These markets synthesise information across many participants and reward precision through genuine financial exposure.
With each election season comes renewed discussion: do prediction markets or polls deliver greater forecasting accuracy? The accumulated evidence points decisively toward markets, and the performance gap continues to widen. Here's what the data reveals.
The track record
Prediction markets have successfully predicted results in numerous prominent contests where conventional polling faltered or proved misleading:
- 2016 US election: Polling aggregates assigned Clinton 70-85% probability. Prediction markets (PredictIt, Betfair) valued Trump's chances at 25-35% — substantially nearer the eventual result
- 2020 US election: Polling suggested a decisive Biden victory. Markets appropriately valued the race as competitive, particularly reflecting volatility across decisive states
- 2024 US election: Polymarket's assessment of Trump (55-65% likelihood heading into the final week) proved more reliable than polling consensus that portrayed the contest as deadlocked
- Brexit 2016: Polling indicated an evenly balanced contest. Prediction markets priced Remain at 75% — both missed the mark, though markets recalibrated more rapidly as results came in
Why markets beat polls
The superiority of prediction markets stems from fundamental structural characteristics rather than random chance:
1. Skin in the game
Survey participants incur no penalty for providing misleading responses. They might misrepresent their views (social desirability bias), respond carelessly, or decline participation (non-response bias). Prediction market participants deploy genuine capital — creating a compelling motivation for rigorous, evidence-based judgement.
2. Information aggregation
Polls solicit predetermined questions from a representative population sample. Prediction markets consolidate information from all willing participants — including political analysts, campaign operatives, quantitative researchers, grassroots observers, and campaign staff. Market valuations synthesise ALL obtainable data, transcending mere survey feedback.
3. Continuous updating
Conventional polling unfolds across multiple days with publication delays. Prediction markets adjust instantly as circumstances evolve. When a politician commits a misstep or an event reshapes sentiment, market valuations shift within seconds.
4. No methodology bias
Polling precision hinges on methodological decisions: demographic adjustment techniques, voter turnout assumptions, question construction. Competing polling organisations generate substantially divergent estimates. Markets circumvent these technical judgements entirely — price discovery manages the synthesis.
When polls still matter
Prediction markets cannot entirely replace conventional polling:
- Thin markets: Low-participation prediction markets risk distortion through large traders or merely echo the convictions of a handful of participants
- Demographic detail: Polls segment opinion across age cohorts, ethnicity, geography — markets furnish solely an aggregate likelihood
- Public opinion (not outcomes): Polls capture citizen sentiment; markets forecast actual results. These represent distinct inquiries
Academic evidence
A 2023 systematic review conducted by scholars at MIT and the University of Pennsylvania demonstrated that prediction markets surpassed polling aggregates in 15 of 17 examined electoral contests spanning half a dozen nations. Performance advantages proved most pronounced in races characterised by elevated volatility and substantial polling divergence along partisan lines.
Monitor live prediction market odds on PolyGram's politics page and observe how markets value forthcoming contests instantaneously. Start trading on PolyGram →