Key takeaway: Empirical research and historical outcomes demonstrate that prediction markets consistently deliver superior accuracy compared to traditional polling when forecasting electoral results and significant global events. Financial incentives embedded in market mechanisms encourage truthful participation and consolidate information from multiple viewpoints.
With each electoral season comes renewed discussion: do prediction markets or polls provide more reliable forecasts? The empirical record leaves little ambiguity — prediction markets emerge as the stronger tool, and this advantage continues to widen. Here's what the numbers reveal.
The track record
Prediction markets have delivered accurate forecasts in numerous prominent contests where conventional polling fell short or produced misleading signals:
- 2016 US election: Polling aggregates assigned Clinton a 70-85% probability of victory. Prediction markets (PredictIt, Betfair) valued Trump's chances at 25-35% — substantially nearer to what ultimately transpired
- 2020 US election: Polling suggested a commanding Biden victory. Markets instead priced a tighter contest, particularly reflecting volatility in decisive swing states
- 2024 US election: Polymarket's assessment of Trump's probability (55-65% in the final seven days) proved more reliable than polling composites that indicated a competitive toss-up
- Brexit 2016: Polling suggested near-parity between options. Prediction markets valued Remain prospects at 75% — neither proved correct, yet markets recalibrated their assessments more swiftly 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 answering poll questions bear no personal cost for providing misleading or careless responses. They may misrepresent their views (social desirability bias), answer without reflection, or opt out entirely (non-response bias). Prediction market participants deploy actual capital — creating a formidable motivation to think carefully and base positions on solid analysis.
2. Information aggregation
Polls operate by posing identical questions to a representative subset of the population. Prediction markets function as open forums where any participant — whether professional analyst, political operative, quantitative researcher, ground-level observer, or campaign staffer — can contribute their assessment through trading activity. The resulting market price incorporates the complete spectrum of obtainable knowledge, transcending mere survey data.
3. Continuous updating
Conventional polls typically require several days to conduct and publication frequently lags collection. Prediction markets respond instantaneously to shifting circumstances. When a public figure commits a misstep or a televised forum alters voter sentiment, market valuations shift within moments.
4. No methodology bias
Poll reliability hinges significantly on technical decisions: how samples are weighted, which model predicts voter turnout, the phrasing of questions. Competing polling organisations frequently generate substantially divergent findings. Markets sidestep these technical judgements — the price mechanism itself performs the aggregation function.
When polls still matter
Prediction markets cannot fully displace conventional polling:
- Thin markets: Markets with modest trading volumes remain susceptible to price manipulation or may simply reflect the convictions of a handful of large traders
- Demographic detail: Polls furnish breakdowns of opinion across age groups, ethnic backgrounds, geographic areas — markets communicate solely a singular probability
- Public opinion (not outcomes): Polls capture what individuals believe; markets forecast what shall occur. These represent distinct inquiries
Academic evidence
A 2023 comprehensive review conducted by scholars at MIT and the University of Pennsylvania examined prediction markets relative to polling aggregates across 17 election cycles spanning six nations. Markets demonstrated superior performance in 15 of these contests. The advantage proved most pronounced in races characterised by elevated unpredictability and instances where partisan polling diverged substantially from reality.
Observe live prediction market valuations on PolyGram's politics page and monitor how markets evaluate forthcoming contests as they unfold. Start trading on PolyGram →