This is a freshly pressed post that appeared September 25 (today) in Policy Options magazine. In it, I describe how the 6-year intelligence forecasting accuracy study that Alan Barnes and I undertook developed. A detailed description of that study was published in a recent PNAS article that was subsequently summarized in this piece in The Economist. Note that the Economist referred to a 76% accuracy rate. That’s wrong. It was 94%, as indicated in the PNAS paper and today’s post. The 76% figure was actually the adjusted normalized discrimination index value, which is akin to an adjusted eta-squared value — namely, the proportion of variance in the outcomes explained by the intelligence forecasts.