Philip E. Tetlock in Project Syndicate:
Every day, experts bombard us with their views on topics as varied as Iraqi insurgents, Bolivian coca growers, European central bankers, and North Korea’s Politburo. But how much credibility should we attach to the opinions of experts?
The sanguine view is that as long as those selling expertise compete vigorously for the attention of discriminating buyers (the mass media), market mechanisms will assure quality control. Pundits who make it into newspaper opinion pages or onto television and radio must have good track records; otherwise, they would have been weeded out.
Skeptics, however, warn that the mass media dictate the voices we hear and are less interested in reasoned debate than in catering to popular prejudices. As a result, fame could be negatively, not positively, correlated with long-run accuracy.
Until recently, no one knew who is right, because no one was keeping score. But the results of a 20-year research project now suggest that the skeptics are closer to the truth.