Patient selection in a mixed oligopoly market for health care: the role of the soft budget constraint

Competition in hospital care is often implemented through mixed markets where public and private hospitals compete for patients. The optimality of this market form has long been debated in the literature. In this paper we investigate the role of soft budget constraint in affecting patient selection within a mixed market. Patient selection is the undesired effect of hospital competition when three conditions are met: asymmetry in hospitals' objectives, presence of hospital’s private information and inability to enforce hard budget constraint. The paper shows that soft budget is a pre-condition for the existence of patient selection. Our paper adds an important dimension to the existing literature which considers asymmetry of information as the only cause for this market failure. The understanding of the mechanisms leading to patient selection makes it possible for the regulator to design measures to reduce such undesirable effect.