The book "ABA Approved Law Schools" shows academic and non-academic attrition rates for every law school. These two numbers tell you very different things. The academic attrition rate tells you how tough the school's grading curve is -- how hard you'll have to struggle just to not flunk out. Academic attrition rates vary from a very pretty "zero" to a terrifying 29%. Non-academic attrition rates show you how many people drop out for other reasons. These are most often financial at some schools, while at others they may be a sign that people have taken on more responsibilities than they can handle. The former is more likely to be true at a school that draws a national student body; the latter would be true at "local" law schools with large part-time populations. These rates again vary from "zero" to over 35%; if you're worried about financing your education, you might want to give these numbers careful consideration.
The list that follows is derived from data given in the ABA book, but is not identical to what is shown there. The ABA book gives an average attrition rate over three years; I think this approach is not very useful, since attrition is cumulative -- i.e., the number of people who don't graduate is the sum of three years' attrition, not the average of it. So I performed my own calculations by adding the attrition rates listed for all three years and dividing it by the number of students in the first year class. This number is not entirely accurate, since it is based on two assumptions:
I know that these two assumptions are false at some law schools, making this list inaccurate to some degree. For instance, if a school had either halved or doubled its first-year class size this year, the second and third year attrition rates I calculated could be half or double the actual number. Since the first year attrition rate would still be accurate, the maximum error is about one-third of the number shown. I.e., if I show a school's attrition rate as 20%, it could be as low as 14% or as high as 30%. More typically, a number will be off by about 10%. I.e., if I show it as 20% it could be 18% or 22%. None of these numbers is "correct," but I prefer them to the 7% the ABA book would show by averaging.
The average cumulative attrition rate for all ABA-approved law schools is 4% academic and 9% other, for a total of 13%. The schools below are listed in order of total attrition rate, from highest to lowest.
2005 NOTE: In 1999, I placed a chart here because the calculation in the ABA book seemed inaccurate. They have since corrected that problem. More recent data is available in the ABA/LSAC Official Guide to Law Schools. It is against my principles to reproduce data that is publicly available; it is probably a violation of copyright law as well. So you'll just have to go look it up.