There's an old joke that if you're being chased by a bear and you want to avoid being eaten, you actually don't have to run faster than the bear. You just have to run faster than the other guy. As it turns out, that joke may be critical to understanding the role college education plays in the modern economy. For a few decades now, economists' ideas about education have been dominated by the "human capital" theory — that more education gives people more skills, which makes them more productive, which means they earn higher wages.