This study tests an implication of the real‐options theory of investment, that uncertainty leads firms to prefer technologies with low fixed and high variable costs. In 1983, a change in Medicare reimbursement increased the uncertainty of revenues for hospitals. Using a sample of 831 departments in 59 Washington State hospitals over the 1977–1994 period, we find that the ratio of variable to total costs increased after 1983. This increase is not attributable to a gradual increase in the ratio over time: We estimate a significant increase after 1983 even after controlling for a time trend. Further, we find a greater increase in the variable‐to‐total cost ratio for hospitals that had higher percentages of Medicare patients, increasing our confidence in the conclusion that the change in cost behavior is attributable to Medicare's change in reimbursement.

Drawing on transaction cost economics and institutional theory we argue that the effects of institutional constraints on the transaction costs of outsourcing vary systematically with the type of service outsourced and the ownership structure of the outsourcing firm. Using data from hospitals, we demonstrate that these effects lead to a higher extent of outsourcing of nonclinical compared to clinical services, and larger outsourcing response of nonclinical services to cost pressures from managed care. Further, the effects of ownership structure and associated governance mechanisms on institutional constraints are reflected in the empirical results as cross‐sectional variations in the extent to which outsourcing is invoked as a response to cost pressures by hospitals of different ownership.