This paper extends Diamond and Dybvig’s model [J. Political Economy 91 (1983) 401] to a framework in which bank assets are risky, there is aggregate uncertainty about the demand for liquidity in the population and some individuals receive a signal about bank asset quality. Others must then try to deduce from observed withdrawals whether an unfavorable signal was received by this group or whether liquidity needs happen to be high. In this environment, both information-induced and pure panic runs will occur. However, banks can prevent them by designing the deposit contract appropriately. It is shown that in some cases it is optimal for the bank to prevent runs but there are situations where the bank run allocation may be welfare superior.

This paper analyzes the effectiveness of different government policies to prevent the emergence of banking crises. In particular, we study the impact on welfare of using taxpayers money to recapitalize banks, government injection of money into the banking system through credit lines, the creation of a buffer and taxes on financial transactions (the Tobin tax). We illustrate the trade-off between these policies and derive policy implications.