OK, thanks for that information. It is very helpful and it appears I was wrong about some things.
A couple points in response. The feds do regulate residency, if only remotely, by requiring that residents be paid (you mentioned Supreme Court precedent finding that they are employees, not students). They also provide the funding.
The question of employee vs. student was about whether hospitals were required to pay their half of payroll taxes on behalf of the residents. The courts said they did,
de facto designating residents as employees. I wouldn't make the leap that - in the absence of federal fundings - residents would go unpaid. The hospitals would still come up with the money, which is exactly what happens now with the handful of training programs that operate outside of the ACGME. As I mentioned before, it introduces variance into the system - with some highly competitive programs getting away without paying people, while others are forced to pay substantially more.
The nongovernmental organizations you mention are basically a manifestation of old rich physicians putting up obstacles to competition by young poor physicians. I'm sure some of them do play a role in protecting the public but at their core, they and trade groups like them are protectionist organizations. To some extent it's beside the point of what we're discussing here, but these kinds of organizations increase the cost of health care by requiring physicians to get extra training and jump through extra hurdles before they are allowed to compete with the established, old, expensive physicians. So here's a new idea for the ideas thread: Let's get rid of some of these protectionist NGOs and allow young physicians to compete in the marketplace on price.
I can't tell if you're conflating the organization I mentioned (ACGME) with politically active groups, like the AMA or specialty-specific groups. Either way, we're wandering a little from my original point on this topic, which was that it's not the federal government who's regulating this. You're right though, the industry restricts entry and costs would come down by removing these hurdles. I do think you're undervaluing the "protecting the public" element though. Even after 3-7 years of residency, most physicians will tell you that there's a steep learning curve once beginning independent practice, and removing these hurdles will make that curve even steeper. If we tear down these obstacles for economic reasons, then we need to be prepared to accept the consequences it has vis-a-vis standard of care and outcomes.
And finally, reflect for a moment on this statement: "most physicians would tell you that their time in residency is a net gain for the system at the expense of the individual." The reason the physicians are willing to serve out residencies is precisely because they want to become a part of that system. That system has historically provided very nice financial rewards for those who get past the various hurdles the profession erects for itself - all of which act to constrain supply, which increases cost. I recognize that primary care providers, ER docs, and others are not making as much as their predecessors of 30 years ago but the fact remains that "the system" provides very nice financial rewards.
I feel like I've already acknowledged this. Your original point seemed to imply that physicians should feel thankful that they don't have to "pay back" the federal government for their GME funding. I've just been trying to explain that I think that's a strange position to take because 1) hospitals - not residents - are not the primary beneficiaries of that funding, 2) the money would come from somewhere, if not the federal government, and 3) residents do "pay back" the time funding by being underpaid for 3-7 years.
Why they do it is largely tangential to the discussion.
In any case getting back to the original point of this discussion, JHMD's idea is still a good one - on top of the existing system, provide an option for docs to get medical school and residency free, no debt, in exchange for an 8 year commitment to provide low-cost care to underserved/uninsured populations. Increase supply.
Lots of programs like this already exist, at both federal and state levels, and usually for an obligation significantly shorter than 8 years. Lots of my wife's fellow residents took U.S. Public Health Service scholarships in exchange for 2-3 years of working in places like Detroit, American Samoa, etc. Hell, even the military will pay for medical school in full for only a 4-year post-training commitment. Pre-medical and medical students know the calculus, and they're still choosing to go massively into debt rather than use these programs.