Prediction Markets - What Are They?

Robin Hanson is an economics professor at George Mason University. He says prediction markets are more reliable than other forecasting methods because they give people incentive to be right and not wrong. In a prediction market, most people don't speak up when they don't know what's going on; that's just the way we want it. If prediction markets have an Achilles heel, it's certainly the possibility that people don't really want accurate forecasts: Just like proposed law against witches in Romania.