Goodheart's law in action: when a metric becomes a target, it ceases to be a good metric. Betting markets might have been useful when the money encouraged hone

Goodheart's law in action: when a metric becomes a target, it ceases to be a good metric. Betting markets might have been useful when the money encouraged honesty. But people are in the market for reasons other money. Conceivably, the market will some day become so big that manipulation costs too much. Today is not that day, and every scam from pari-mutuel betting is out in force.