Think you can predict the future? Good luck. In his new book The Signal and the Noise, statistician Nate Silver--he of the New York Times's FiveThirtyEight blog, who called the 2008 presidential election with near perfection--says to question your faith in many trusted prediction methods. Here are four:
1. ECONOMIC INDICATORS
"They're one hot mess," Silver says. The government produces data on 45,000 indicators annually, but few are anything more than correlation. And folklore indicators--like which team wins the Super Bowl--receive routine press attention but are almost always bogus.
2. EXPERT OPINIONS
After conducting a survey of 1,000 predictions made by panelists on the TV show The McLaughlin Group, Silver concluded that so-called experts display as much acumen as "a barbershop quartet." The pundits, he says, were no better than a coin flip.
Back in 2009, as cases of H1N1 went from 20 to 2,618 in two weeks, U.S. authorities described a plausible scenario in which half the population became infected, leading to 90,000 American deaths. The strain (thankfully) turned out to be exceptionally mild, with just a 0.02% fatality rate.
Commercial meteorologists deliberately overestimate the likelihood of rain, forecasting a 20% chance when there's only a 5% to 10% chance. Why? It's a way of "covering their butts," Silver says.
Illustration by Vidhya Nagarajan