Derek Muller (Pepperdine), Solving Law School Admissions; or, How U.S. News Distorts Student Quality:
Brian Leiter has noted elsewhere that LSAT and GPA are "highly manipulable" by law schools. But I'd like to focus on a slightly different area: the distortion of student quality by the reporting of medians.
A student, after all, has both an LSAT score and a GPA. But the USNWR ranking isolates LSAT and GPA. An incoming class under USNWR, then, is no longer the composite of students; it is the composite of LSAT scores and GPAs, each independently evaluated.
At the same time, schools are still trying to accept the "best" students, and they need a metric for identifying the "best." Each school often has an "index" formula, which combines LSAT and GPA into a single number, weighting each differently.
So there's a metric schools use to identify the "best" students, calculated by their indices; and there's a metric that USNWR uses to identify the selectivity of each institution, calculated by isolating LSAT and GPA medians. What happens when the two don't align? ...
There are two "wings" blocked out in blue. The smaller wing at the top of each chart includes those with above-median GPAs and below-median LSAT scores, who appear to be accepted at a relatively high rate. The larger wing at the bottom includes those with below-median GPAs and above-median LSAT scores, who also appear to be accepted at a relatively high rate. ...
But what about those in the "donut hole"? These are high-quality candidates—that is, they are very close to the index line of the school, comparable to many others who are admitted. There is virtually no chance at these students being accepted: their odds are worse than 10% each year. But their peers with comparable—or worse—index scores, but who have a higher isolated GPA or LSAT score, are admitted at dramatically higher rates. It is because the students in the "donut hole" are "below-below" candidates; they cannot assist the school's LSAT or GPA medians.
In the end, this is where USNWR drives law school admissions. They admit students in the "wings," but exclude students in the "donut hole"; and they not only accept students in the "wings" with comparable index scores over those in the "donut hole," they accept students with worse index scores. Schools accept students they believe to be "worse" than these "donut hole" candidates—and not by some subjective understanding, but based upon their own preexisting index formula designed to measure student quality—in an effort to secure students who have one LSAT score or GPA that meets or exceeds a target median they intend to report to USNWR.