Banks face two moral hazard problems: asset substitution by shareholders (e.g., making risky, negative net present value loans) and managerial rent seeking (e.g., investing in inefficient “pet” projects or simply being lazy and uninnovative). The privately-optimal level of bank leverage is...

We develop a theory of optimal bank leverage in which the benefit of debt in inducing loan monitoring is balanced against the benefit of equity in attenuating risk-shifting. However, faced with socially-costly correlated bank failures, regulators bail out creditors. Anticipation of this...