Supplementary private health insurance: The impact of physician financial incentives on medical practice

In the French diagnosis‐related group (DRG)‐based payment system, both private and public hospitals are financed by a public single payer. Public hospitals are overcrowded and have no direct financial incentives to choose one procedure over another. If a patient has a strong preference, they can switch to a private hospital. In private hospitals, the preference does come into play, but the patient has to pay for the additional cost, for which they are reimbursed if they have supplementary private health insurance. Do financial incentives from the fees received by physicians for different procedures drive their behavior? Using French exhaustive data on delivery, we find that private hospitals perform significantly more cesarean deliveries than public hospitals. However, for patients without private health insurance, the two sectors differ much less in terms of cesareans rate. We determine the impact of the financial incentive for patients who can afford the additional cost. Affordability is mainly ensured by the reimbursement of costs by private health insurance. These findings can be interpreted as evidence that, in healthcare systems where a public single payer offers universal coverage, the presence of supplementary private insurance can contribute to creating incentives on the supply side and lead to practices and an allocation of resources that are not optimal from a social welfare perspective.