In the past few weeks, colleges have started reporting the racial makeup of the first class admitted after the Supreme Court ended affirmative action in 2023.

While it’s tempting to try to compare the numbers coming out from different colleges, it’s difficult to do so based on what we know so far.

Take the share of Black students reported by Harvard and Princeton: Harvard reported that this figure declined to 14 percent in its incoming class this year, from 18 percent last year. And Princeton reported that its share of Black students remained at 9 percent.

If you didn’t read the fine print, you might reasonably assume that although the share of Black students declined only at Harvard, it’s still much higher than the share at Princeton. But they are actually much closer than these figures suggest.

The reason: When reporting these figures to the public, many colleges use different formulas to calculate their racial makeup, an often overlooked fact.

If that sounds surprising, the explanation is that there is no single, obviously “correct” way to report race. Do you include international students? If so, how? If a student identified as both Black and white, do you count them only as multiracial, or do you also count them in each race? And does your pool include students who didn’t submit a race?