Depression is pervasive in the US particularly among women. The costs in terms of direct medical costs and forgone earnings are substantial. This paper investigates an additional cost of depression. Using data from the National Longitudinal Survey of Adolescent Health, we use a unique instrument, the attacks of September 11, which have been linked to depression, to identify the effect of depression on risky sexual behaviors. We find that depressed women are more likely to be sexually active, to engage in oral sex and to have sex without a condom, even after controlling for a rich set of covariates.

We implemented a randomized field experiment in Malawi examining borrower responses to being fingerprinted when applying for loans. This intervention improved the lender's ability to implement dynamic repayment incentives, allowing it to withhold future loans from past defaulters while rewarding good borrowers with better loan terms. As predicted by a simple model, fingerprinting led to substantially higher repayment rates for borrowers with the highest ex ante default risk, but had no effect for the rest of the borrowers. We provide unique evidence that this improvement in repayment rates is accompanied by behaviors consistent with less adverse selection and lower moral hazard.

Systemic risk must include the housing market, though economists have not generally focused on it. We begin construction of an agent-based model of the housing market with individual data from Washington, DC. Twenty years of success with agent-based models of mortgage prepayments give us hope that such a model could be useful. Preliminary analysis suggests that the housing boom and bust of 1997-2007 was due in large part to changes in leverage rather than interest rates.