Well, doesn’t the relative size on that thing matters and it was back in 2012. I think Emory takes into account endowment, overlap in applications, and maybe many other factors (like professional schools available, etc). Emory recently (maybe 3-4 years ago) redid its peers to cut out some of the aspirational peers (like Harvard, Yale, and that group I think. More realistic aspirational peers include places like Duke, Northwestern, and some of the lower Ivies I think) because unlike some of its closely ranked peers, it isn’t quite as delusional (most private schools historically below 12 or so in USNWR are merely dreaming when they list HYS as peers, no matter how many programs overlap) at this point. I think it realizes that even if it looked like those schools on paper admissions selectivity wise at some point, it still has to do lots of real (vs. superficial) work to get even close. Others will just show shiny incoming stats and say: “see we’re Harvard now” even when every other indicator says: “No you’re Emory, you just used admissions to game the rankings” lol.
It makes way more sense for maybe even UCLA, Berkeley, and Michigan to do so on the other hand do to the historical overall impact of those schools on highered and how it seems that many of the super elite private undergraduate schools model things such as their STEM programs and such off of theirs, just done for a more selective crowd). The endowment and impact isn’t there, but Brandeis and Rochester make less sense today and may view Emory more of an aspirational peer at this point.
Again, that says less about the individual undergraduate programs and more about overall research strength and money of course. There are peer schools that rank a little above Emory in USNWR, where Emory probably has stronger undergraduate programs in many areas (I think some evidence suggests that Emory hurts in rankings and admissions pull due to lack of an engineering school, but things like the BBA program, this relatively new QTM program, quite a few social sciences, key humanities like English/Creative writing, and many of the natural sciences can clean the clocks of a some of those places because and unusual amount of money is put into those departments specifically for undergraduate education and oppurtunities).