People skills, pre-meds, medical students and doctors

Of course, the cost of medical school (resulting in new MDs with $300,000 in debt) and the limited number of residency slots (despite government subsidy of such) are factors that create the shortage and are unlikely to be changed by going completely free market. We import foreign-educated MDs because many of them do not have the debt levels that US-educated MDs have, so they can afford to go into lower paid specialties (e.g. the primary care ones), particularly in poorer regions.