Here on Manifold we have a storied and sordid history of looking for ways to resolve a prediction market without any sort of operator intervention.

The hope is that this will let us create markets about questions for which there's no way to get an externally-verifiable answer. 

In the interests of completeness I am testing this latest model. Cancelling a market upon completion removes the profit incentive at the heart of prediction markets, but at the same time, a poll weighted by users' past betting performance seems like it would have a good shot of ourperforming typical polls, and may be worth exploring as a model.