Saving the public from the private? Incentives and outcomes in dual practice

We consider a monopoly physician offering free public treatment and, if allowed, a private treatment for which patients have to pay out of pocket. While patients differ in the propensity to benefit from private treatment it always yields better health outcomes than public treatment but is also more costly in terms of money and time. We study the physician's supply of private care and allocation of time costs across public and private patients and contrast these with the first‐best allocation. To increase the willingness‐to‐pay for private treatment the physician shifts time costs to public patients. While this turns out to be socially optimal, the resulting positive network effect leads to an over‐provision of private care if time costs are sufficiently high. A second‐best allocation arises when the health authority sets public reimbursement but has no control over private provision. Depending on the welfare weight the health authority attaches to physician profits, a ban of dual practice may improve on the second‐best allocation. Notably, a ban benefits not only public patients but also private patients with a moderate propensity to benefit from private care.