We study physician agency and optimal payment policy in the context of an expensive medication used in dialysis care. Using Medicare claims data we estimate a structural model of treatment decisions, in which physicians differ in their altruism and marginal costs, and this heterogeneity is...

We study a credence goods problem - that is, a moral hazard problem with non-contractible outcome - where altruistic experts (the agents) care both about their income and the utility of consumers (the principals). Experts' preferences over income and their consumers' utility are convex, such...