Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
Health systems are employing physicians in growing numbers. The implications of this trend are poorly understood and controversial. We use rich data from the Centers for Medicare and Medicaid Services to examine the effects of a set of physician acquisitions by hospital systems on outpatient utilization and spending. We find that financial integration systematically produces economically large changes in the acquired physicians’ behavior, but has less consistent effects at the acquiring system level.