Talent retention is not a key driver of economic vitality. If it were, Chicago and New York City would be in a world of trouble. But that doesn't stop many from resorting to the tired brain drain refrain.
Top-tier research universities matter more than a vibrant urban core as focus shifts from talent attraction (too much competition) to talent production.
Why a proposal in Michigan to subsidize education for students who remain in-state after graduation won't benefit anybody. It's brain gain we should worry about, not brain drain.