Cesarean delivery for low-risk pregnancies is generally associated with worse health outcomes for infants and mothers. The interpretation of this correlation, however, is confounded by potential selectivity in the choice of birth mode. We use birth records from California, merged with hospital...

Treatment practices vary widely across hospitals, often with little connection to the medical needs of patients. We assess impacts of these differences in childbirth, where there is broad interest in reducing cesarean deliveries. Using a distance-based design and data from half a million births,...