DAVID LEONHARDT DEFENDS THE ECONOMIC VALUE OF COLLEGE in the New York Times, and Arnold Kling comments:

Or, perhaps, college filters out people with low cognitive ability, low conscientiousness, and other adverse traits. I want to see an experiment, in which some people are randomly chosen to go to college and others are chosen not to go to college. Then, proceed to compare outcomes. Meanwhile, nonexperimental data is of little or no value. . . . My elitism comes from the few years I spent as an adjunct at George Mason. The typical undergrad in my course could not write a paper or solve an algebra problem. I doubt that adding more students at this margin is the way to raise people’s incomes.

Somebody should run the experiment on a small scale, before we embark on a grand social policy on this.

Read the whole thing.

UPDATE: Reader Fred Butzen writes:

To answer Arnold Kling’s post, there already is a control group for his college/no-college experiment: the cohort of young people who enlist in the armed forces out of high school. I would say that those who complete a four-year tour in the armed forces emerge at least as motivated and at least as skilled as those who’ve spent four years studying liberal arts in college – or arguably, more so. Still, to some employers, a degree in philosophy (my major, back in the day) has more appeal than four years spent doing the difficult, dangerous work of defending our nation. Go figure.

Hmm.