Competition and regulation.

Perhaps as a reflection of the current medical care environment and governmental budgetary stringencies, cost containment is a major source of policy concern. There are some who would argue that one should have a comprehensive understanding of how the medical care system works in order to design appropriate policies to improve its performance. As other articles in this volume demonstrate, there is still much we do not know about individual aspects of the medical care system, and no article even attempts a comprehensive discussion of the system. Policymakers, however, cannot await research findings, and there have been numerous policy interventions in the last two decades aimed at cost containment.