France has additional factors mitigating against a potential flood of medical-care-seekers: 1) Most (all?) other countries in the EU don't have terrible Americ

France has additional factors mitigating against a potential flood of medical-care-seekers: 1) Most (all?) other countries in the EU don't have terrible American-style systems of healthcare provision, so the pull isn't as strong. 2) Language barriers make e.g. a Poland-to-France move more difficult than a Missouri-to-California move, even though the latter move actually requires covering a greater geographic distance. Of course there are practical barriers against every medically underserved American moving to California to take advantage of a single payer system. My intuition is that there could easily be enough of them to more than cancel the economic benefits that you'd expect from imitating the successful single payer systems of other countries. YMMV. I'd love to be wrong about this. EDIT: dragonwriter brought up a good point about business-magnet effects, which offsets some of my pessimism about the outcomes of trying this in California. And you have a good point about Californians who might be able to re-enter the workforce.