
Philip Tetlock found a surprising result when testing teams of experts to predict future events. After years of tracking how well these teams did in forecasting significant events or developments in countries, he found they did little better than random chance…about as well as “a dart-throwing chimpanzee.” A big problem, however, was that these experts were very poor at estimating their own effectiveness. People usually have much more confidence in their beliefs than is warranted.

Wise decision-makers strive for “Strong opinions, weakly held.” In other words, they commit to their beliefs, and act on them. But they remain open to the distinct possibility of being wrong. The three hardest words for experts to say are “I don’t know.”
Listen to a Freakonomics podcast about making better predictions here.
Watch Professor Tetlock talk about expert forecasters here: