The regression results for the individual data show that there is a significant (at the 5% level), albeit a smaller relationship between LSAT scores and starting salaries than there is for the cross-- school model. Among the students in one school, one point on the LSAT is worth only about oneseventh of what it is worth in the cross-school model. These results indicate that six-sevenths of the variance is being used up in the screening effects of the school. Law schools have the ability to put more energy into screening students than do law firms. Law firms assume that in general, students attend the highest quality school into which they were admitted. Therefore, the true effect of one point on the LSAT is greater than can be measured within one school.

However, in terms of lifetime income, the spread is still a significant difference even within one school. A student with a higher LSAT score, should, on average, make more money than a student who scored lower and attended the same law school. Between schools, the spread is larger. If a student scored in the top 5% on her LSAT and went to a top 5% school, she would be earning a higher salary, on average, than if she attended a lower ranking school.

V. Distortions of the LSAT's Predictive Value-LSAT Prep Courses

Since one LSAT point is worth thousands of dollars to the test-taker, it is obvious why the LSAT prep course industry is thriving with approximately $30,000,000 in revenue off courses alone every year. (One course costs $700-$800.) The commercial prep course market is dominated by two firms, Kaplan and Princeton Review. Competition for clients between the firms is a melodrama of its own, with unprofessional name-calling and ad falsification that results in costly arbitration. Both firms also sell study aids in the form of books and computer disks, as do several other companies and the Law School Admissions Council.

Kaplan claims a 7.2 point increase in scores for their LSAT prep course (Coleman). Kaplan, who claimed to have no special dialogue with U.S. News & World Report in a phone interview, is co-sponsor of their graduate school issue. Princeton Review claims a 7.5 point increase in scores for their LSAT prep course. Both claims are backed up by studies from prestigious accounting firms.

What about people who don't take a commercial prep course and use study aids instead? According to studies administered by Law School Admissions Services (LSAS), those using official Law Services test preparation materials (old tests) have the highest LSAT mean as a group than any group using other study methods. LSAS sells old tests at $6 a test. In general, those spending $800 on a prep course do not have higher LSAT scores than do those using much cheaper study aids.

However, these statistics do not show if commercial prep course users have a greater relative advantage than if these courses did not exist at all. Is it the study method that determines final LSAT score or is it the type of people that take prep courses that lower the mean LSAT score for the group? To answer this question, I conducted a survey among Washington University law school students to determine score improvement among those using Kaplan, Princeton Review, and book aids. My results show that Kaplan raises scores 5.7 points, Princeton Review raises then 5.5 points, and book aids raise them 2.5 points (see Appendix 5). Final mean LSAT scores for those using prep courses and those using book aids varied by only one point, with those taking prep courses having a slightly lower LSAT mean. Furthermore, regression analysis showed that the amount of time and money put into studying for the LSATs is actually inversely related to higher LSAT scores. This phenomena is not due to any adverse effects of studying. Those who spend more time and money on studying for the LSAT will end up with lower scores because they started out with lower scores in the first place, and while studying will raise their score, it will not raise it above those who do inherently better on the LSAT