We charge immigrants the non-resident tuition rate, so whether they come from California, China or Canada makes no financial difference to me (I'm in Michigan). Their tuition subsidized my kid's tuition fees; they don't need to pay me back any more than that. Our domestic students also benefit from the exposure to other cultures when visitors study here. The fact that grad students return home doesn't bother me.

If non-resident tuition is not enough to cover the true expense of education, I say raise the rate - don't expect graduates to stay here when there is so much work to be done in their home countries.