Its pretty clear they are not at all merit based with the exception of Caltech.
In fact, just the opposite at the Ivies. Its very clear that admissions are extremely biased against Asians and non-Jewish whites.
This is a loong article but its worth it. Read it ALL the way.
http://www.theamericanconservative.com/articles/the-myth-of-american-meritocracy/The author is very fair and all the cites check out.
The overwhelming evidence is that the system currently employed by most of our leading universities admits applicants whose ability may be unremarkable but who are beneficiaries of underhanded manipulation and favoritism. Nations which put their future national leadership in the hands of such individuals are likely to encounter enormous economic and social problems, exactly the sort of problems which our own country seems to have increasingly experienced over the last couple of decades.
