[CTG1983]

Yes, it is true that, int'l students are not favored as much as the domestic students. I have heard from a relative of mine who did his PhD from top-10.
The reason they show is that: for mba diversity is a big issue, but not so in case of PhD. And they don't want to spend money for foreigners. Spending money for domestic students is like a service to the nation.

But this was a purely personal opinion. The admissions statisctics of top schools for PhD suggests this, though. The (admission/no. of applications) is certainly greater for domestic students than for int'l students. Simply, it can't be claimed that int'l students are less smart or brilliant. In fact, they show higher commitment to research.