Key takeaway: Empirical studies and historical outcomes demonstrate that prediction markets consistently surpass traditional polling in forecasting electoral results and significant events. These markets synthesise information across multiple channels whilst creating financial incentives that reward accuracy and penalise error.
With each electoral campaign, the question resurfaces: do prediction markets or polls deliver superior accuracy? The empirical record now points decisively in one direction — markets have the edge, and that advantage continues to expand. The reasoning, supported by data, follows below.
The track record
Prediction markets have successfully predicted outcomes where conventional polling faltered or produced misleading signals across numerous significant contests:
- 2016 US election: Polling aggregates assigned Clinton probabilities between 70-85%. Competing prediction markets (PredictIt, Betfair) assigned Trump likelihoods of 25-35% — substantially more aligned with the eventual result
- 2020 US election: Polling consensus projected a decisive Biden victory. Market-derived probabilities more accurately captured the tightness of the contest, particularly in decisive swing states
- 2024 US election: Polymarket assessments placing Trump at 55-65% probability in the final trading week outperformed aggregated polling data that characterised the race as genuinely uncertain
- Brexit 2016: Polling indicated an essentially even split. Prediction markets priced Remain at 75% — neither proved prescient, though market prices recalibrated more swiftly as results materialised
Why markets beat polls
The superiority of prediction markets over polls stems from fundamental structural differences rather than chance variation:
1. Skin in the game
Survey respondents incur no personal cost from providing misleading or careless responses. Respondents may misrepresent their preferences (social desirability bias), answer without reflection, or decline participation altogether (non-response bias). Prediction market participants commit capital — an exceptionally strong motivator for rigorous analysis and truthful positioning.
2. Information aggregation
Polls pose a predetermined questionnaire to a representative sample. Prediction markets consolidate signals from any participant willing to trade — including academic researchers, political operatives, quantitative analysts, ground-level observers, and campaign personnel. The resulting market price encodes ALL discoverable information, transcending the constraints of survey-based collection.
3. Continuous updating
Conventional polling occurs across multi-day windows and reaches publication only after processing delays. Prediction markets reflect new information instantaneously as participants transact. When a candidate commits a public misstep or a televised discussion shifts sentiment, market valuations shift within seconds.
4. No methodology bias
Poll reliability hinges on technical choices: demographic weighting schemes, voter-likelihood algorithms, question construction. Competing polling organisations frequently diverge sharply in their outputs. Markets circumvent these technical decisions altogether — price discovery operates independently of methodological assumptions.
When polls still matter
Prediction markets cannot entirely displace traditional polling:
- Thin markets: Low-liquidity prediction markets remain vulnerable to manipulation or may simply echo the convictions of dominant traders
- Demographic detail: Polls furnish granular breakdowns across age cohorts, ethnic groups, and geographic zones — markets deliver only aggregate likelihood figures
- Public opinion (not outcomes): Polls quantify citizen sentiment; markets forecast what shall occur. These represent distinct analytical objectives
Academic evidence
A 2023 systematic review conducted by scholars at MIT and the University of Pennsylvania examined prediction market performance relative to polling aggregates across 17 distinct electoral contests spanning six nations. Markets demonstrated superior accuracy in 15 of the 17 cases examined. The performance differential proved most pronounced in contests characterised by elevated outcome uncertainty and substantial polling divergence along partisan lines.
Monitor live prediction market valuations via PolyGram's politics page and observe how markets assess forthcoming developments in actual time. Start trading on PolyGram →