The note in Science says the price quotes in idea futures "correlate well" with actual outcomes, where known. That's reassuring. It does not say how well this correlation compares with that for other methods of prediction such as nonmonetary polling, delphic surveys of expert opinion, discussion and debate or direct scholarly study of particular questions.

Many of the predictions in the Ideas Futures used at the Foresight Gatherings have the form "Some world-changing event will happen by such-and-such a year." For example, I have seen predictions about when the nation-state will cease to have power or the nanoassembler will arrive utterly changing economics. The absurdity is that to collect on Ideas Futures requires stability. The duty of people to pay me when my contract in the Ideas Futures comes to term is enforced by the nation-state of a stable economy. The fact that these kinds of question are even permitted in Ideas Futures makes it very un-serious. Logically, in any "disruption" scenario, I will always put as much money as possible on the outcome which says that the disruption doesn't happen, because if I'm right, I will collect and if I'm wrong, the disruption will mean there is no institution left to force me to pay up.