How should colleges decide which students to admit?

There’s a 2-in-3 chance if you ask a random American, the response will be “pure merit.”

Those odds rise to 3-in-4 if the random American happens to be white.

Of course, college admissions decisions aren’t based purely on test scores. Currently, admissions officers consider a range of factors, including race and ethnicity, musical or athletic talent, geographic location, whether the parents are alumni, and, frankly, whether they can pay the full sticker price.

One problem with moving from the status quo to a pure merit system is that it would level a giant blow to diversity. But, while the status quo produces more diversity than does a system of pure merit, it turns out not to be much better.

What could actually increase racial diversity at America’s top universities, relative to the current status quo, is shifting to a class-based affirmative action model.

How Enrollment Models Stack Up

Pure merit would be pretty poisonous to diversity. Eliminating every factor but test scores from admissions decisions would make entering classes whiter and overwhelmingly upper-class.

A pure merit approach would increase the percentage of white students at the nation’s top 193 colleges from 74 percent to 83 percent, according to new research from Anthony Carnevale, Stephen Rose, and Jeff Strohl. Meanwhile, the percentage of African American and Hispanic students would decrease.

One group would be even more overrepresented than whites under a pure merit system: the rich.

Under a pure merit system, 65 percent of students would come from the wealthiest quarter of Americans, while just 5 percent would come from the poorest quarter.

So, if pure merit is not an improvement on the status quo, where can colleges turn to improve diversity? Moving to race-blind alternative systems that explicitly factor in socioeconomic disadvantage would actually increase black and Hispanic enrollment relative to the status quo, while also increasing average SAT scores.

Even better, the various alternatives tested by Carnevale, Rose, and Strohl would increase the percentage of students from the bottom socioeconomic quarter from 5 percent under the status quo to between 13 and 22 percent.

The research here is really pretty conclusive: If you care about ensuring racial, ethnic, and economic diversity at America’s best colleges, the status quo is better than using test scores alone as a criteria … but worse than pretty much everything else.

Affirmative Action Enrollment Plans

Status Quo: Admissions are generally merit-based, with additional considerations for children of alumni (aka, legacy admissions) and for members of underrepresented racial and ethnic groups (aka, affirmative action).

Pure Merit: Admissions are based on test scores alone, with no additional considerations for legacy students or for affirmative action.

Pure Merit Plus Socioeconomic Status: Admissions are based on test scores, with additional considerations for overcoming various socioeconomic disadvantages such as parental education, income, savings—a proxy for wealth—and neighborhood factors such as school poverty concentrations.

Top 10% Plan: A merit-based policy in which the top 10% of students in each high school are automatically admitted.

Top 10% Plan Plus Socioeconomic Status: A merit-based policy in which the top 10% of students in each high school are automatically admitted, with additional preferences for overcoming various socioeconomic disadvantages such as parental education, income, savings—a proxy for wealth—and neighborhood factors such as school poverty concentrations.