<p>You should factor in the average size of the FA grant. As Soxmom pointed out, % of students on aid isn’t a meaningful comparison without that information. </p>
<p>Endowments often carry restrictions. So, for all I know, some of the schools might have separate funds for taking care of church towers, or mowing the football fields, or procuring fetal pigs for biology courses. The money which is available for FA could be significantly smaller than the size of the endowment.</p>
<p>You would also need to correct somehow for different percentages of day and boarding students. I don’t regard ECs and sports as extras, as it helps to keep kids out of trouble if they’re doing something supervised by an adult. The boarders don’t go home, and everyone sleeps better at night if the teenagers go to bed tired.</p>
<p>The more boarders a school has, the more people they need to supervise the dorms. I don’t think there’s a separate line for that? And new buildings cost less to maintain and run than old buildings.</p>