A student's law school application is composed of several parts. It includes a grade point average and a Law School Admissions Test score. It includes an undergraduate institution, and major or majors. It may include the candidate's sex, race, ethnicity, national origin, work experience, sexual orientation, post-graduate education, military history, religious affiliation, and anything else a school requests or an applicant desires to include (usually in a personal statement). Schools compete for applicants and want to create the best class they can. A school's definition of "best" can include a number of factors, but LSAT and GPA are usually two of the most significant.



The U.S. News & World Report annually ranks law schools. Almost a quarter of the ranking is based on the median LSAT and GPA of the entering class. This is intended to ascertain how "selective" the school is.



Professor 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?



Solving law school admissions



In order to solve law school admissions, we'll need admissions data. Schools, understandably, don't disclose this data. So we'll use the next best thing: LawSchoolNumbers.com. (I'm grateful to myLSN.info for help in aggregating LSN's data.)



Prospective students have voluntarily submitted over 250,000 data points over the last 10 years to LSN. Even if it's self-reported, it's a valuable resource for examining admissions.



I took a large, fairly selective law school as the basis for this examination. (You could probably find the school easily, but its identity is irrelevant to this analysis.) For fun, here's an animated GIF (from MakeAGif.com) of the last ten years of admitted students (with data from the 2012-2013 cycle through last month).