There's always a trade-off. You can have cheap steel, or well paid steel workers. You can have cheap medical care, or well paid doctors. Arguably by making pos

There's always a trade-off. You can have cheap steel, or well paid steel workers. You can have cheap medical care, or well paid doctors. Arguably by making postdocs underpaid, the US as a nation is getting cheap scientific advancement, in exchange for dangling the promise of eventual American citizenship (and the American dream) in front of said postdocs.