How prediction markets often beat the experts

HostI was looking at how we try to guess the future lately, whether it's who will win a big game or which way an election might go. We usually turn to the pros, the people in suits on the news who get paid to have big opinions, but there's this other way that seems to get it right way more often. It's just a bunch of people putting their own money down on what they think will happen.

HostWhy is a group of people placing bets so much better at seeing what's coming than a single person who has studied the topic for their whole life?

GuestIt sounds backward, right? We're taught to trust the person with the most degrees or the longest resume. But the big problem with those pros is that they don't really lose anything if they're wrong. If a talking head on TV makes a wild guess and it fails to happen, they still get their paycheck. They might even get more famous for being bold. In a betting market, or what a lot of people call a prediction market, everything changes because you have skin in the game. If you make a bad guess, you lose your cash. That threat of losing money forces people to be much more honest with themselves. They stop betting on what they want to happen and start betting on what they truly think will happen.

HostI get the part about being honest, but it still feels like a gamble. I mean, we don't look at the poker tables in a casino to tell us how the world is going to work next year.

GuestWell, there's a big difference between a game of cards and a market. In a market, people are trading on facts. Think of it like a giant machine that gathers up tiny scraps of clues from thousands of different people. There's a famous story about a fair back in the early nineteen hundreds. A crowd of eight hundred people tried to guess the weight of a huge ox. Some guessed way too high, and some guessed way too low. None of the experts there got it right. But when you took the average of every single guess from the crowd, it was within one pound of the real weight. The crowd, as a whole, knew something that no single person knew. Markets do that same thing every minute of the day.

HostBut wait, that sounds like you're saying a crowd of random people is just naturally smarter than a scientist or a researcher. That feels a bit hard to believe. If I want to know about a new virus, I'm going to ask a doctor, not a guy in a betting pool.

GuestYou should definitely ask the doctor for the science, but if you want to know how fast that virus will spread across the whole country, the market might give you a better lead. Here is why. The doctor knows the science, but someone else knows about how the schools are run, and someone else knows how many people are actually staying home, and another person knows about shipping delays. No one person can hold all those facts at once. A market lets the doctor, the truck driver, and the school teacher all "vote" by placing a bet. When they do that, all those little bits of local knowledge get baked into one single number, which is the price.

HostSo the price is like a score that shows the total of everything everyone knows?

GuestExactly. It's like a thermometer for the truth. If I know a secret piece of news, like a company's new phone is breaking in tests, I'm going to bet that their stock price will go down. I don't have to write a news story or go on TV. I just place my bet. As soon as I do that, the price moves a little bit. Other people see the price move and they start to wonder what's going on. The market "finds" the truth because it gives people a reason to find it first. It turns searching for the truth into a way to make a buck.

HostThat feels a bit shady, though. If someone has a secret and they bet on it, they're basically getting rewarded for having an unfair jump on everyone else. Is that really the best way to run things?

GuestIt might feel unfair to the person who doesn't know the secret, but for the rest of us, it's actually a huge help. We get to see the price change in real time. The market acts like an early warning system. Most experts are slow. They have to write a report, get it checked by their boss, and then publish it. By the time you read it, the news is old. A market reacts the second someone learns something new. It's the fastest way in the world to move a piece of news from one person's head to everyone else's eyes.

HostBut people are emotional. We see this in the stock market all the time where everyone panic buys or panic sells just because they see everyone else doing it. Doesn't that just turn these betting pools into a big popularity contest?

GuestThat can happen for a little while. We call those bubbles. But the cool thing about these markets is that they have a built-in fix for that. If the price of a bet gets too high because people are just being fans, it creates a huge chance for a smart person to come in and bet against them. If you know a popular team is actually going to lose, and their price is sky high because their fans are betting with their hearts, you can make a lot of money by betting the other way. Those smart, cold-hearted bets eventually push the price back to where it should be. The pros on TV often get stuck in a bubble of their own because they all talk to each other. People in a market are trying to beat each other, which keeps them sharp.

HostSo the expert is trying to be right to look good, while the person in the market is trying to be right to take the other guy's money.

GuestThat's a harsh way to put it, but it's pretty much the truth. The market doesn't care how famous you're or where you went to school. It only cares if you're right. It's a place where a person who knows one small, true thing can win against a celebrity who's just guessing.

HostThose betting pools might look like a game from the outside, but they're really just a way of looking at the world through thousands of different eyes at once.

GuestThe real secret is that the market doesn't care why you're right, it just rewards the person who saw the truth first.

HostThe next time I see a bunch of people in suits making big guesses on TV, I'll be checking the betting lines to see what the people putting up their own cash actually think.