Banks can create liquidity precisely because deposits are fragile and prone to runs. Increased uncertainty makes deposits excessively fragile, creating a role for outside bank capital. Greater bank capital reduces the probability of financial distress but also reduces liquidity creation. The quantity of capital influences the amount that banks can induce borrowers to pay. Optimal bank capital structure trades off effects on liquidity creation, costs of bank distress, and the ability to force borrower repayment. The model explains the decline in bank capital over the last two centuries. It identifies overlooked consequences of having regulatory capital requirements and deposit insurance.

We model the distortions that internal power struggles can generate in the allocation of resources between divisions of a diversified firm. The model predicts that if divisions are similar in the level of their resources and opportunities, funds will be transferred from divisions with poor opportunities to divisions with good opportunities. When diversity in resources and opportunities increases, however, resources can flow toward the most inefficient division, leading to more inefficient investment and less valuable firms. We test these predictions on a panel of diversified U.S. firms during the period from 1980 to 1993 and find evidence consistent with them.