Actually,
I think I need to side with Wildcat on this one. looking deeper into the issue, it's clear that the AMA has actively sought to limit the number of doctors produced as a means of salary controls.
http://www.usatoday.com/news/health/2005-03-02-doctor-shortage_x.htm
I've just lost a lot of respect for the profession.
Here is the current line from the article:
Even the American Medical Association (AMA), the influential lobbying group for physicians, has abandoned its long-standing position that an "oversupply exists or is immediately expected."
But this is really besides the point, because AMA doesn't actually control the number. Their power is mostly as advisory. And only 15% of doctors are members of the AMA (wiki).
Going back to the USAToday article about the real limits for having more doctors, you are looking at Government Subsidies. The lack of them is creating the shortage. Which is quite frankly a direct result of people not wanting to "throw money at the problem".