Hospital response to prospective payment: moral hazard, selection, and practice-style effects.

In response to a change in reimbursement incentives, hospitals may change the intensity of services provided to a given set of patients, change the type (or severity) of patients they see, or change their market share. Each of these three responses, which we define as a moral hazard effect, a selection effect, and a practice-style effect, can influence average resource use in a population. We develop and implement a methodology for disentangling these effects using a panel data set of Medicaid psychiatric discharges in New Hampshire. We also find evidence for the form of quality competition hypothesized by Dranove (1987).