Richard Kahlenberg never stops promoting his idea that what the nation needs is a big push for class-based preferences in college admissions. Most recently, he wrote this post for the Chronicle’s Innovations blog.

“Affirmative action still matters a great deal even if it only prevents a ‘slide down the ladder’ from Yale to Waterbury . . . because the experiences at different colleges can alter a student’s trajectory,” Kahlenberg writes. “As I’ve noted elsewhere, controlling for various factors, attending a selective institution is associated with increased rates of graduation and increased wages, particularly for low-income and minority students. And selective institutions disproportionately provide entree into America’s leadership class.”

So, what Kahlenberg favors is that schools such as Yale should admit applicants who otherwise would not have the academic profile for admission just because they come from poor families. They should do so because those students will then benefit from a) a somewhat higher likelihood of graduation, b) a somewhat higher paying initial job, and c) an increased likelihood of becoming one of the nation’s leaders.

I guess that Kahlenberg believes his approach will enhance equality and make the country more “socially just.” I disagree.

First, whether a student graduates or not isn’t a matter of probability. Rich or poor, if you do what the college requires to graduate, you graduate. Second, it’s no doubt true on average that Yale graduates start at higher salaries than do Waterbury graduates, but there’s no guarantee of that. It might work the other way. A student who could major in math at Waterbury but shies away from it at Yale in favor of some softer, less competitive field, might be worse off taking the latter course. In any event, in the long run, an individual’s earnings don’t depend on his academic credentials, but on his own performance. And third, what reason is there to suppose that the country will be better off if it has more leaders whose families were relatively poor? As Barack Obama abundantly proves, coming from a non-affluent background does not ensure wise leadership. Neither, of course, does an affluent background. Let’s abandon the notion that social engineering of the student bodies at top colleges accomplishes anything of value.