Key takeaway: Empirical research and historical performance data reveal that prediction markets consistently outperform traditional polling in forecasting electoral outcomes and significant events. Markets synthesise information from multiple channels and reward accuracy through tangible financial consequences.
Each election season brings renewed discussion: do prediction markets or polls deliver superior forecasting? The empirical record leaves little doubt — prediction markets emerge victorious, with their advantage widening over time. Here's what the numbers tell us.
The track record
Prediction markets have delivered accurate forecasts in numerous high-stakes situations where traditional polls faltered or miscalculated:
- 2016 US election: Polling organisations assigned Clinton 70-85% win probability. Prediction markets (PredictIt, Betfair) valued Trump's chances at 25-35% — substantially nearer the ultimate result
- 2020 US election: Polling projections anticipated a decisive Biden victory. Markets priced the outcome as considerably tighter, appropriately reflecting competitive dynamics in key states
- 2024 US election: Polymarket's assessment of Trump at 55-65% probability during the final fortnight proved more reliable than polling consensus that portrayed the race as essentially even
- Brexit 2016: Polls indicated an essentially even contest. Prediction markets assigned Remain a 75% probability — whilst both proved inaccurate, markets corrected their assessments more swiftly as results emerged
Why markets beat polls
The superiority of prediction markets over polling stems from fundamental structural differences, not mere chance:
1. Skin in the game
Respondents to polls bear no risk for providing misleading information. They may misrepresent their views (social desirability bias), respond haphazardly, or decline participation (non-response bias). Prediction market participants invest actual capital — creating robust incentives for careful, evidence-based decision-making.
2. Information aggregation
Polls solicit responses to predetermined questions from randomly selected participants. Prediction markets consolidate insights from all willing participants — academic researchers, political operatives, quantitative analysts, ground-level observers, campaign personnel. Market valuations incorporate the totality of available knowledge, extending well beyond survey data alone.
3. Continuous updating
Polling typically occurs across multiple days with publication delays. Prediction markets adjust instantaneously as conditions evolve. When a candidate commits a significant error or debate performance reshapes sentiment, market valuations shift within moments.
4. No methodology bias
Polling reliability hinges substantially on methodological choices: demographic adjustment techniques, voter turnout assumptions, survey design. Competing polling organisations frequently generate substantially divergent estimates. Markets circumvent these methodological considerations entirely — price determination manages the synthesis organically.
When polls still matter
Prediction markets cannot entirely displace traditional polling:
- Thin markets: Markets with modest trading activity remain susceptible to manipulation or may simply reflect the convictions of dominant participants
- Demographic detail: Polls provide granular breakdowns across age cohorts, ethnic groups, geographic areas — markets furnish solely an aggregate likelihood
- Public opinion (not outcomes): Polls quantify prevailing attitudes; markets forecast eventual results. These represent distinct inquiries
Academic evidence
A 2023 comprehensive 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 six nations. Performance gaps widened most dramatically in elections characterised by substantial unpredictability and systematic polling inaccuracies tied to partisan factors.
Monitor live prediction market valuations on PolyGram's politics page and observe how markets assess forthcoming contests as they unfold. Start trading on PolyGram →