TLDR
- A Brennan Center for Justice study found Kalshi prediction market odds change who voters think will win an election.
- A candidate at 84% odds was 20% more likely to be picked as the likely winner than one at 50% odds.
- Only 19% of voters called prediction markets accurate, compared with 37% for traditional polls.
- Warnings about the limits of prediction markets did not reduce voters’ reliance on the odds.
- Ohio is preparing legal action against Kalshi and Polymarket after issuing cease-and-desist notices.
A new study shows that prediction market odds can change how voters see an election, even when those voters do not trust the numbers.
The research comes from the Brennan Center for Justice. It looked at how odds from Kalshi, a prediction market operator, affect what people expect to happen in a race.
How the Study Worked
Researchers asked respondents to pick the likely winner in pairs of hypothetical congressional races. Each candidate came with background details such as race, age, party and past job.
Respondents also saw two estimates of each candidate’s chances of winning. One came from NBC News polling, and the other came from Kalshi.
The researchers randomly changed the polling figures and the Kalshi odds. This let them test how people reacted when the two sources disagreed.
The results showed that Kalshi odds shaped voter expectations. Candidates with higher odds on Kalshi were more likely to be seen as the winner.
A candidate with a 67% chance of winning on Kalshi was 10% more likely to be named the likely winner than a candidate at 50%. When the odds rose to 84%, that figure climbed to 20%.
The study also tested whether warnings could reduce this effect. Respondents were told about the limits of prediction markets, but the warnings did not lower their reliance on the odds.
Skeptical Voters Still Swayed
Many voters in the study said they do not trust prediction markets. Only 19% called election prediction markets accurate, compared with 37% who said the same about traditional polls.
Just 29% said prediction markets accurately reflect public opinion. By contrast, 55% said conventional polls do.
Even so, the data showed that these skeptical voters were still influenced by the odds when judging who would win.
Prediction market odds have become easier for the public to find. Through partnerships with CNN, CNBC and Fox News, the odds now often appear next to polling numbers or in place of them.
The two types of figures are produced in very different ways. Polls survey voters, while prediction market odds come from people trading contracts on the outcome of events.
The Brennan Center for Justice says its findings point to a need for stricter regulation of prediction markets.
Respondents showed some support for that view. About 48% favored stricter rules, while 23% supported banning certain types of prediction markets.
Another 16% said all types of prediction markets should be banned.
Several states are already moving to regulate the sector on their own. Ohio is preparing legal action against Kalshi and Polymarket after the Ohio Casino Control Commission issued cease-and-desist notices to both companies and others.
