Here’s Why Prediction Markets Aren’t Used For Anything Important

Tyler Cowen has a question:

Why doesn’t business use more prediction markets? They would seem to make sense, right? Bet on ideas. Aggregate information. We’ve all read Hayek.

Hal Varian’s answer is that the most valuable predictions are very sensitive, and you don’t want those to be public. My answer is different: prediction markets are too easy to game. They work decently as long as no one really cares about the answer, but as soon as someone does care—i.e., someone can make a lot of money from influencing the results—then the prediction market will be rigged. The only way to stop that from happening is to make the market expensive, but then you lose almost all your players.

It’s hard to rig the actual market because the cost of rigging it is usually higher than the amount of money you can make from rigging it. But as soon as that cost drops so much as a nano-penny lower, someone, somewhere will decide to screw with it.


We recently wrapped up the crowdfunding campaign for our ambitious Mother Jones Corruption Project, and it was a smashing success. About 10,364 readers pitched in with donations averaging $45, and together they contributed about $467,374 toward our $500,000 goal.

That's amazing. We still have donations from letters we sent in the mail coming back to us, so we're on pace to hit—if not exceed—that goal. Thank you so much. We'll keep you posted here as the project ramps up, and you can join the hundreds of readers who have alerted us to corruption to dig into.

We Recommend


Sign up for our newsletters

Subscribe and we'll send Mother Jones straight to your inbox.

Get our award-winning magazine

Save big on a full year of investigations, ideas, and insights.


Support our journalism

Help Mother Jones' reporters dig deep with a tax-deductible donation.


Share your feedback: We’re planning to launch a new version of the comments section. Help us test it.