"We only ranked metropolitan areas (the cities and their suburbs) of 1 million people or more, using Census data, with the definition of each greater metropolitan area defined by Nielsen. That gave us 55 in all. All data was then organized on a per-capita basis, so that a resident of Norfolk, Virginia, and New York, New York, had equal weight. We’re looking for the brainiest cities, not the biggest.
Then we divided the criteria into two halves: Half for education, and half for intellectual environment. The education half encompassed how many residents had bachelor’s degrees (35 percent weighting) and graduate degrees (15 percent). No credit was given for “some college,” or “some grad school”—we rewarded those who finished the race. The intellectual environmental half had three subparts. First, we looked at nonfiction book sales (25 percent), as tracked by Nielsen BookScan, the nation’s leading provider of accurate point-of-sale data, which tracks roughly 300,000 titles each week. We focused on nonfiction as an imperfect proxy for intellectual vigor, because overall sales are dominated by fiction works that, while entertaining, aren’t always particularly thought-provoking. We also measured the ratio of institutions of higher education (15 percent), as defined by the federal government—different than just measuring college degrees, this acknowledges that universities don’t just churn out diplomas, but instead drive the intellectual vigor of cities.
Finally, many studies link intelligence and political engagement, so we weighed this, too, as measured by the percentage of eligible voters who cast ballots in the last presidential election (10 percent). (Our relatively small weighting acknowledges that numerous other local factors can affect turnout.)
Once we had all these comparable, per-capita figures, we ranked the cities in each category, assigning 10 points to those near the very top, and 0 to the bottom, with scores allocated between in a broad bell curve. We then added the totals, and multiplied by two, which made for a perfect score of 200, a wash-out score of 0, and an average score right at 100—close to the exact parameters of a classic IQ test."
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