If you are one of the people who criticise prediction markets on their accuracy in forecasting the Brazilian election, I have a question for you:
What should Lula's odds have been before voting started in Brazil?
Should it have been 50.1%?
Maybe 100%, because the universe is deterministic and Lula ended up winning?
Clearly I'm being facetious, but here are the facts:
- Bolsonaro won round 1 by a significant margin, and the split was expected to favour him over Lula.
- This is the first time a candidate who lost in round 1 managed to win in round 2 in Brazils history, in all 7 earlier presidential elections the winner of round 1 went on to win.
Bolosnaro was clearly the favorite. But should he have been 60% instead of 80%? Maybe 70%? Based on what? These are questions you have to answer if you are going to talk about prediction market odds being wrong about the Brazil election!
How are they theoretically findable? How could you possibly get this information? Even if you went out of your way and you personally did door to door knocking in Brazil—a very impractical thing to do, you are going to have a very significant margin of error.
You would then find it very useful to come up with a probabilistic forecast like 'Lula has a 30% chance of winning the election'. And you would have a hard time accounting for corruption, things like voting being extended by two hours a couple minutes before it was supposed to close, and only in certain locations.
This is not different from sports! The main difference is that sports is more knowable than elections, it's much more of a 'solved game'.
people comparing this to sports or poker or dice are dumb. elections aren't pure random draws. they just compress collective attitutes into a single vote.
the facts that would crystallize in the outcome were knowable before. they were theoretically findable, and there was a big incentive to find them. yet no one did.
@DenialLaw Yeah they swung 10 points to the left since the first round, happens. In May 2025 I lost 120k+ betting on George Simion because in the first round he got ~41% of the vote and Nicusor Dan got ~21%. Guess what happened round 2?
@DemNationalist It may be true that prediction market odds are inaccurate and completely detached from reality.
But how does a screenshot of a candidate with 15-20% odds winning prove that?...