In a laboratory experiment with 754 participants, we study the canonical one-shot moral hazard problem, comparing treatments with unobservable effort to benchmark treatments with verifiable effort. In our experiment, the players endogenously negotiate contracts. In line with contract theory, the...

We study optimal direct mechanisms for a credence goods expert who can be altruistic or spiteful. The expert has private information about her distributional preferences and possibly also about her customer's needs. We introduce a method that allows the customer to offer separate contracts to...

Information asymmetries are important in theory but difficult to identify in practice. We estimate the empirical importance of adverse selection and moral hazard in a consumer credit market using a new field experiment methodology. We randomized 58,000 direct mail offers issued by a major South...

We study the long-run impacts of health insurance promotion in Northern Ghana. We randomly provide three overlapping interventions to promote enrollment: subsidy, information campaign, and convenient sign-up option, with follow-up surveys seven months and three years after the initial...