It's hard to make predictions, especially about the future: why dart-throwing chimps are better than the experts.

• Author: Bailey, Ronald

THE PRICE OF OIL will soar to $200 a barrel. A bioterror attack will occur before 2013. Rising food prices will spark riots in Britain. The Arctic Ocean will be ice-free by 2015. Home prices will not recover this year. But who cares about any of those predictions? The world will end in 2012.

The media abound with confident predictions. Everywhere we turn, an expert is sounding the alarm bells on some future trend. Should we pay much attention? No, says journalist Dan Gardner in his wonderfully perspicacious new book, Future Babble: Why Expert Predictions Are Next to Worthless, and You Can Do Better (McClelland & Stewart).

Gardner acknowledges his debt to the Berkeley psychologist Philip Tetlock, who in 1985 set up a 20-year experiment involving nearly 300 experts in politics. Tetlock solicited thousands of predictions about the fates of scores of countries and later checked how accurate they were. He 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."

In this excellent book, Gardner romps through the last 40 years of failed predictions on economics, energy, environment, politics, and much more. Remember back in 1990, when Japan was going to rule the world? The MIT economist Lester Thurow declared, "If one looks at the last 20 years, Japan would have to be considered the betting favorite to win the economic honors of owning the 21St century" Thurow was far from alone. In 1992 George Friedman, now CEO of the geopolitical consultancy Straffor, predicted The Coming War With Japan. (In case you are hungry for more predictive insights from Friedman, he has recently published The Next 200 Years: A Forecast for the 21st Century.)

As oil prices ascend once again, many naturally predict that the end of this energy source is nigh. Back in 1980, Gardner reminds us, The New York Times confidently declared: "There should be no such thing as optimism about energy for the foreseeable future. What is certain is that the price of oil will go up and up, at home as well as abroad." By 1986 oil prices had fallen to around $10 a barrel. On the general accuracy of oil price predictions, Gardner cites U.S. Foreign Service officer...