Information aggregation mechanisms are designed explicitly for collecting and aggregating dispersed information. An excellent example of the use of this “wisdom of crowds” is a prediction market. The purpose of our social network-embedded prediction market is to suggest that carefully...

For two periods an expert E announces his forecast of the state to a decision-maker D who chooses action. They disagree about the precision of the probability assessments. At the end of period 1 the state is observed. In the last period E makes announcements more extreme than his forecasts....