the loans. We thank four anonymous referees and the editor, Costas Meghir, for extremely helpful comments. Thanks

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 African lender along three dimensions: 1) the initial "offer interest rate " appearing on direct mail solicitations; 2) a "contract interest rate " equal to or less than the offer interest rate and revealed to the over 4,000 borrowers who agreed to the initial offer rate; and 3) a dynamic repayment incentive that extends preferential pricing on future loans to borrowers who remain in good standing. These three randomizations, combined with complete knowledge of the Lender's information set, permit identification of specific types of private information problems. Our setup distinguishes adverse selection from moral hazard effects on repayment, and thereby generates unique evidence on the existence and magnitudes of specific credit market failures. We find evidence of moral hazard and weaker evidence for adverse selection. A rough calibration suggests that perhaps 15 % of default is due to asymmetric information problems. This may help explain the prevalence of credit constraints even in a market that specializes in financing high-risk borrowers at very high rates

Heterogeneity and Tests of Risk Sharing

How well do people share risk? Standard risk-sharing regressions assume that any variation in households’ risk preferences is uncorrelated with variation in the cyclicality of income. I combine administrative and survey data to show that this assumption is questionable: Risk-tolerant workers hold jobs in which earnings carry more aggregate risk. The correlation makes risk-sharing regressions in the previous literature too pessimistic. I derive techniques that eliminate the bias, apply them to U.S. data, and find that the effect of idiosyncratic income shocks on consumption is practically small and statistically difficult to distinguish from zero.