[timr]

"Radiology is a very difficult field to get into after medical school, something like 2/3 of American grads who apply get turned away."

I don't agree with kenjackson that the field can be self-taught, but saying that most people don't get into Radiology residencies tells me only that there aren't enough Radiology residencies to go around. The 1/3 board failure rate notwithstanding, my intuition is that there are far more people capable of practicing radiology than are currently allowed to try to get into the field. The intelligence level of medical students does not exceed that of PhD students in engineering, math, chemistry, etc., but the medical profession puts up much, much higher economic barriers to entry.

If the government decided to tax radiology providers and use the profits to increase the number of radiology residencies by 10 or 100-fold, I find it hard to believe that the lucrative profit margins of your industry wouldn't decline. Medicare reimbursement rates would go down as the number of providers increased.