Get A Bigger Grain Of Salt

Andrew Sullivan —  Apr 11 2011 @ 10:30am

Ronald Bailey reviews Dan Gardner's new book, Future Babble: Why Expert Predictions Are Next to Worthless, And You Can Do Better:

Gardner acknowledges his debt to political scientist Phililp Tetlock, who set up a 20-year experiment in which he enrolled nearly 300 experts in politics. Tetlock then solicited thousands of predictions about the fates of scores of countries and later checked how well they did. Not so well. Tetlock concluded that most of his experts would have been beaten by “a dart-throwing chimpanzee.” Tetlock found that the experts wearing rose-tinted glasses “assigned probabilities of 65 percent to rosy scenarios that materialized only 15 percent of the time.” Doomsters did even worse: “They assigned probabilities of 70 percent to bleak scenarios that materialized only 12 percent of the time.”

I fear I'm in the latter position. But at least I get constantly to be pleasantly surprised.