I can't speak to overall statistical numbers, but of the 75+ international graduate students that I've spoken to, I would estimate at least 85% plan to stay in the U.S.

I find this particularly surprising given that their status is essentially that of indentured servants; their advisors can deport them at any time with only 14 days of notice. This one-way power dynamic can produce cruel, callous treatment and merciless working hours, both of which I've observed first-hand. And yet, these same professors will turn around and collaborate politely and respectfully with American students (assuming that they will take on American students in their labs; many will not!).

It's really very depressing.