Moral Hazard in the Diamond - Dybvig

Working papers of the Federal Reserve Bank of Cleveland are preliminary materials circulated to stimulate discussion and critical comment on research in progress. They may not have been subject to the formal editorial review accorded official Federal Reserve Bank of Cleveland publications. The views stated herein are those of the authors and are not necessarily those of the Federal Reserve Bank of Cleveland or of the Board of Governors of the Federal Reserve System. and the participants at the conference in honor of Neil Wallace. In addition, they received several useful comments from seminar participants at various schools. They would especially like to thank Neil Wallace for many enjoyable hours of conversation regarding money and banking—conversations that greatly influenced the content of this paper. David Andolfatto acknowledges the financial support of SSHRC. We modify the Diamond-Dybvig model studied in Green and Lin to incorporate a self-interested banker who has a private record-keeping technology. A public record-keeping device does not exist. We find that there is a trade-off between sophisticated contracts that possess relatively good risk-sharing properties but allocate resources inefficiently for incentive reasons, and simple contracts that possess relatively poor risk-sharing properties but economize on the inefficient use of resources. While this trade-off depends on model parameters, we find that simple contracts prevail under a wide range of empirically plausible parameter values. Although moral hazard in banking may simplify the optimal structure of deposit liabilities, this simple structure does not enhance the prospect of bank runs.