IEM noted as successful prediction market

Prediction markets come in many stripes, but most work by allowing people to bet -- by buying and selling futures contracts -- on the likelihood of future events, with the result that the market price of those contracts reflects traders' collective forecast of how likely an event is to occur. Some prediction markets seem to do a good job of predicting the future, in matters both small and large. Since 1988, when it first began, the University of Iowa's IOWA ELECTRONICS MARKET has consistently outperformed polls in predicting presidential elections.