timelets

“If the forecast said there was a 70% chance of rain and it rains, people think the forecast was right; if it doesn’t rain, they think it was wrong. This simple mistake is extremely common. Even sophisticated thinkers fall for it. In 2012, when the Supreme Court was about to release its long-awaited decision on the constitutionality of Obamacare, prediction markets—markets that let people bet on possible outcomes—pegged the probability of the law being struck down at 75%. When the court upheld the law, the sagacious New York Times reporter David Leonhardt declared that “the market—the wisdom of the crowds—was wrong.”

Philip E. Tetlock. “Superforecasting.”