We develop a model where banks invest in reserves and loans, and trade loans on the interbank market to deal with liquidity shocks. Two types of equilibria emerge, depending on the degree of credit market competition and the level of aggregate liquidity risk. In one equilibrium, all banks keep enough reserves and remain solvent. In the other, some banks default with positive probability. The latter equilibrium exists when competition is weak and large liquidity shocks are unlikely. The model delivers several implications concerning the relationship between competition, aggregate credit, and welfare.

Loan guarantees represent a form of government intervention to support bank lending. However, their use raises concerns as to their effect on bank risk-taking incentives. In a model of financial fragility that incorporates bank capital and a bank incentive problem, we show that loan guarantees reduce depositor runs and improve bank underwriting standards, except for the most poorly capitalized banks. We highlight a novel feedback effect between banks’ underwriting choices and depositors’ run decisions, and show that the effect of loan guarantees on banks’ incentives is different from that of other types of guarantees, such as deposit insurance.