The stakes don't need to be high to encourage strong participation. OK but strong participation isn't necessarily a positive for the accuracy of a market. The

The stakes don't need to be high to encourage strong participation. OK but strong participation isn't necessarily a positive for the accuracy of a market. The problem is the prediction market with lots of participants can be just outlet for partisans to put forward their opinions. There's a tax on wrong opinions but someone is spending a bucks, the markets won't be a powerful force for changing those opinions. What you want for a prediction market is for the major participants to actively researching the problems - expend money and effort to have a well founded reason for their positions. Markets for random real-world events have the problem that many events don't occur often to weed out arbitrary biases and there may not be any easy or cost effect way to attain a well-founded opinion on the subject.