HMO penetration and the geographic mobility of practicing physicians

In this study, we assessed the influence of changes in health maintenance o rganization (HMO) penetration on the probability that established patient c are physicians relocated their practices or left patient care altogether. F or physicians who relocated their practices, we also assessed the impact of HMO penetration on their destination choices. We found that larger increas es in HMO penetration decreased the probability that medical/surgical speci alists in early career stayed in patient carl in the same market, but had n o impact on generalists, hospital-based specialists, or mid career medical/ surgical specialists. We also found that physicians who relocated their pra ctices were much more likely to choose destination markets with the same le vel of HMO penetration or lower HMO penetration compared with their origin markets than they were to choose destination markets with higher HMO penetr ation. The largely negligible impact of changes in HMO penetration on estab lished physicians' decisions to relocate their practices or leave patient c are is consistent with high relocation and switching costs. Relocating phys icians' attraction to destination markets with the same level of HMO penetr ation as their origin markets suggests that, while physicians' styles of me dical practice may adopt to changes in market conditions, learning new prac tice styles is costly. (C) 2000 Elsevier Science B.V. All rights reserved.