A tool for collating group opinions (as they change over time) about well defined events using market principles.

• Prediction_market
• http://www.gwern.net/Prediction%20markets
• http://www.overcomingbias.com/2006/12/the_80_forecast.html
• http://ashokarao.com/2013/07/04/on-bets/
• http://predictionbook.com/
• long bets
• http://wrongtomorrow.com
• futarchy