Changes in physician supply and scope of practice during a malpractice crisis: evidence from Pennsylvania.

The extent to which liability costs cause physicians to restrict their scope of practice or cease practicing is controversial in policy debates over malpractice "crises." We used insurance department administrative data to analyze specialist physician scope-of-practice changes and exits in Pennsylvania in 1993-2002. In most specialties the proportions of high-risk specialists restricting their scope of practice did not increase during the crisis; however, the supply of obstetrician-gynecologists decreased by 8 percent in the three years following premium increases in 1999. We discuss methodological issues that could explain the disparate findings regarding physician supply effects in studies using administrative data sets and survey data.