The yields are deceiving when comparing directly between these top three (HYS) largely because the Harvard class is simply so huge (about 550 students, more than 3X the size of each of SLS and YLS). Therefore, YLS and SLS (each with entering classes of about 175 students) can’t possibly offer admission to all the students admitted to HLS (nor, apparently, do they want to), given the sheer size of the entering Harvard class. Therefore, simple mathematics mandates that the number of cross-admits between Harvard and Yale and Harvard and Stanford–on a percentage basis–is not nearly what most would assume it to be (i.e., the overlap is necessarily much smaller).
As a result, Harvard admits a significant portion of their class with students who never received offers from Yale or Stanford. I suspect many on this forum would be surprised at the sheer number of HLS acceptances who were ultimately choosing between HLS and Virginia, or HLS and Michigan, or HLS and Georgetown, or HLS and NYU/Columbia, or HLS and Chicago or Berkeley. Even a fair number end up choosing between HLS and Texas or HLS and Vanderbilt or UCLA. Obviously, these are all great law schools, and, in each case, a fantastic “final two” law schools to be deciding between. But the choice for HLS for many (certainly not all) of those applicants, is therefore an easier proposition. Even then, a fair number choose UVA or Chicago or Michigan or Columbia, sometimes because scholarship $ becomes an important factor. Obviously, there is still H/Y and H/S overlap, but it simply can’t be as large on a percentage basis as it is between Y and S (which have almost identical class sizes and frequently are looking for similar outside accomplishments). Therefore, the Harvard yield number, in many ways, is really not directly comparable to YLS or SLS yields–and is artificially inflated upwards (due to its large class size and its more frequent cross admit battles with the rest of the T14 (minus Y and S))–for this reason.
The Yale/Stanford overlap, % wise, is quite high, because both are part of the HYS triumvirate AND have almost identical class sizes (resulting in many students who value the smaller class size focused on both schools), AND both schools tend to look for major accomplishments beyond LSAT and GPA, the two metrics upon which Harvard has long placed the greatest emphasis.
Most of the cross-yield information is pretty tightly guarded among these three. If you talk to students at ASW–or even among your friends from college who applied to HYS–you’ll typically find a disproportionate number of HLS admits who were not accepted to Y or S, again, the HLS huge class size being a major factor. (Obviously, there is overlap among the three, but in terms of sheer numbers, and on a percentage basis, given the huge size of the HLS class, HLS has far more “final 2” overlaps with other T14 law schools.) A major percentage of both YLS and SLS enrolees were also accepted to HLS. On a percentage basis, again–given the sheer size of the HLS entering class–the same cannot be said about HLS enroless with respect to YLS and SLS.
Needless to say, most of this is driven by the fact that the class sizes between the Big Three are so distinctly different, with HLS by far being one of the biggest law schools in the Country.
Word is (and because it’s word of mouth, it’s nothing I can link–so take it for what it’s worth) that YLS continues to beat both SLS and HLS fairly comfortably for cross admits (although the # has been declining in recent years for a variety of reasons). Nevertheless, both SLS and HLS take a meaningful number of admits from YLS every year, but YLS is still top among those extremely confident they want to pursue academia. For many years, Yale benefitted in cross-admit battles with S and H due to their perceived relaxed, “no grades” (not exactly accurate) policy; again, this perception and advantage has apparently slowly started to change. SLS and HLS, on the other hand, have–for many decades–historically split their direct cross-admit pool, but apparently SLS has moved ahead over about the past 10 years. And, perhaps not surprisingly, HLS continues to win a disproportionate number of the significant number of HLS vs. other T14 (i.e., not including Y or S) competitions, to fill out its entering class of 550+.
Bottom line: HLS yield will always be artificially inflated upward when compared directly to YLS and SLS because of the sheer size of its entering class (about 550-575 students), a meaningful number of whom simply chose HLS over other T14 members, and didn’t have the YLS or SLS option.