This article below is just an op-ed. The author doesn't rely on any study, but it's the kind of topic that many folks like to ask about.

In the end, however, how well the LSAT predicts future success is not that important because law schools think it does a good job. So the better your score, the better your school. And there is actual evidence, contrary to some comments posted after the article, that law-school rank and post-graduation salary are positively correlated.

Here are some comments from Stanford Law School worth quoting:

Stanford's website offers a refreshing dose of honesty when it professes, "Admissions officers downplay the role of the LSAT in admissions decisions, but don't believe them." Stanford claims further that a "perfect GPA, an abundance of extracurricular activities, and a background as unique as an honest politician will not get you into a top-five law school if your LSAT score is low."

Here's the full article:

LSAT Score Fails to Determine Quality

Although it's not too surprising, an interesting study conducted in 2004 suggests that the LSAT does a better job of predicting how well you'll do on in-class tests than on take-home exams or assigned papers.

This power to predict, however, is important to admissions committees because most of your law school GPA depends on in-class tests. In fact, most classes base your grade on nothing but one three-hour final exam at the end of the semester. Much like your LSAT score, your grade depends on one great performance.

The study concludes that the LSAT's time constraints make it most similar to in-class exams. In short, speed matters on the LSAT and in law school.

Your GPA, on the other hand, does a good job of predicting how well you'll do in all three scenarios -- in-class exams, take-home exams, and assigned papers -- which is probably why law schools look at your GPA right after they look at your LSAT score. These numbers aren't perfect, but they start to reveal what you've done in the past and what you'll likely do in the future.

That said, preparing for the LSAT does more than just prepare you for the test itself. Students who invest themselves develop the very skills the exam is testing. And that prepares you for law school.

For those who are interested, here's the original study:

Speed as a Variable on the LSAT and Law School Exams

Beware, it's a 3 MB PDF.