Fighting hand to hand over physician workforce policy.

A vexing problem in health policy is getting the right number of physicians in the right specialties in the right locations at the right time. I examine market and public planning approaches to getting the number "right." After discussing the basic premises of the invisible hand of the market and the heavy hand of government regulation, I apply these concepts to a review of the past century of U.S. physician supply and workforce policy. I conclude by examining recent health system trends that make clear the need for a firm regulatory grasp on physician workforce policy.