By "infrastructure" do you mean boarding, ie. their room? And then I suppose the loans are for food and incidentals?

One of the weird parts of the US higher education system is that at the very top private schools, things are cheaper than anywhere in Europe for low and middle income families - not only no tuition, but free food, free housing. For other expenses (books, computer, trips home, a modest amount of other spending) they calculate what it will cost, deduct the amount you'd earn working ten hrs/wk at a low paid job plus some summer earnings, and give you the rest. These are grants, not loans. At the same time the public higher education system has been getting ever more expensive, and only a minute fraction of students can get into one of the top schools. Furthermore, due to a combination of better pre  university education for the upper middle class and wealthy, plus the 'legacy' system, the poor and middle class are at a distinct disadvantage in the admissions process.