Such a claim requires that (a) students—and, presumably, their parents—have good, solid knowledge about what constitutes the best college, (b) the affordability of all the options is equivalent, and (c) there’s a single definition of “best”.
In order:
[ul] The fact that we’re having the discussion in this thread—and the folks here are pretty well-informed on this sort of topic!—as well as arguments about college quality elsewhere on CC makes for some pretty good anecdotal evidence that nobody really knows what constitutes the best (however defined) colleges. Where information about the market is incomplete, distortions in market choices abound.
Different colleges provide (especially after financial aid of all sorts) different price points. To the extent that affordability is an issue for any of the highest-ranked students, that introduces a distortion in the market independent of quality of institution (however defined), and thus means that you can’t really rely on student choice to distinguish college quality.
[li]{c) This is, arguably, the big one. For my D17, no college over about 4,000 students could fit her definition of “best”; for my D19, bigger is better. For my D19, a college can’t be “best” if it doesn’t have a student orchestra than non-majors can audition for; that wasn’t even an issue for my D17. (And for both of them, those aren’t issues of fun or somesuch—they show, to them, dedication to aspects of educational quality.) For some students, there has to be a really amazing musical theater program, or an engineering program, or a strong pre-med track. For some, a location in a “college town” is a big deal, or a huge city, or the middle of nowhere. And so on.[/ul][/li]Not to mention that the issues of perceived quality vs. actual quality can be a pretty big avenue for distortion, as well.