Without going through every one of them (acknowledging there may be one with cutting edge, recent data), I would hesitate to put too much credence into the studies listed in post #9, as the data analyzed does not reflect the current college admissions climate.
The first and most commonly cited study - Kreuger and Dale - is a good example. The study is based on the outcomes of people who entered college in 1989. Does anybody here think the college applications process, the admissions process and selectivity, accessibility of top colleges for nontraditional students and even the resources offered at top selectives vs state unis from 1989 even remotely resembles the current situation?
In the late '80s, the distribution of top students was less concentrated since in many areas top students hadn’t even heard of many of these colleges and those that did had little access. An example would be the math prodigy from outside NE or CA and was more likely to have gone to his/her state U than a top selective. With the internet, rankings and programs designed to allow first gen and nontraditional students access to the top selectives, this has completely changed in the last ten years. That same math prodigy would be likely to apply to and attend a top selective than the state U. At the same time, the offerings and quality of the programs at the top schools has accelerated while funding for many state Us has languished. IMO, all this will contribute to a widening of the outcomes for the people who entered college since 2005 or so. It will be many years before we have enough history to analyze that data, though.
Can top students get top quality education at schools other than the most highly sought after? Yes! Of course. There will be smart kids at every school. But I think the generalization that outcomes are roughly equal for every school will not hold true in the future given the increasing polarization and rush to the top.
How does that play out for the mid-tier? Tough to guess. My bet would be that certain mid-tier schools will become top tier and the rest remain regionally known with commensurate results for graduates depending on if they want to stay in the region in which they graduated.