Banks' leverage choices represent a delicate balancing act. Credit discipline argues for more leverage, while balance-sheet opacity and ease of asset substitution argue for less. Meanwhile, regulatory safety nets promote ex post financial stability, but also create perverse incentives for banks...

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...