What caused the financial crisis that is sweeping across the world? What keeps asset prices and lending depressed? What can be done to remedy matters? While it is too early to arrive at definite answers to these questions, it is certainly time to offer informed conjectures, and these are the focus of this paper.

We examine the role of banks in the transmission of monetary policy. In economies where banks use real demand deposits to finance their lending, fluctuations in the timing of production can force banks to scramble for real liquidity, or even fail, which can greatly affect lending and aggregate output. The adverse effect on output can be reduced if banks finance with nominal deposits. Nominal deposits also open a “financial liquidity” channel for monetary policy to affect real activity. The banking system may be better off, however, issuing real deposits (e.g., foreign exchange denominated) under some circumstances.

the 2002 meetings of the American Economics Association. Governments sometimes bail out banks by recapitalizing them, or offering to insure their liabilities. The government’s goal may be to rescue borrowers, bankers, or depositors – and economists have developed rationales why each of these constituencies may merit protection (e.g., Diamond [2001)). These potential benefits have to be weighed against the costs of a bailout, which are typically thought to be those of the damage to long-run incentives that such intervention engenders. In this paper, we would like to present a different effect of bank bailouts: Bank bailouts alter the availability of aggregate liquidity in the economy. While a well-targeted bailout can help rescue an otherwise collapsing banking system (see Diamond-Rajan [2001a]), a poorly targeted bailout can even tip a banking system into a systemic crisis. This (ex-post crisis) cost of bank bailouts has, to the best of our knowledge, not been examined elsewhere, and is the focus of this paper. The Framework We consider a world with entrepreneurs, investors, and lenders. The economy lasts for two periods and three dates-- date 0 to date 2. There are two kinds of goods in the economy-consumption goods and machinery. Each entrepreneur has a project, requiring 1 unit of

Banks perform valuable activities on either side of their balance sheets. On the asset side, they make loans to difficult, illiquid borrowers. On the liability side, they provide liquidity on demand to depositors. But there seems to be a fundamental incompatibility between the two activities: the demands for liquidity by depositors may arrive at an inconvenient time and force the fire-sale liquidation of illiquid assets. Furthermore, because depositors are served in sequence, the prospect of fire sales may precipitate self-fulfilling runs that further jeopardize bank activities. Is this an aberration, stemming from historical accident, and enshrined by deposit insurance? Or is there logic, hitherto unnoticed, for the bank’s choice of activities? Our recent work suggests that the answer to the latter question is yes. In order to describe why a bank’s fragile capital structure allows it to create liquidity and to explain why bank loans are illiquid, we present a simple example based on Diamond and Rajan (2001a).

We show in this article that bank failures can be contagious. Unlike earlier work where contagion stems from depositor panics or contractual links between banks, we argue that bank failures can shrink the common pool of liquidity, creating, or exacerbating aggregate liquidity shortages. This could lead to a contagion of failures and a total meltdown of the system. Given the costs of a meltdown, there is a possible role for government intervention. Unfortunately, liquidity and solvency problems interact and can cause each other, making it hard to determine the cause of a crisis. We propose a robust sequence of intervention.

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.

Banks finance illiquid assets with demandable deposits, which discipline bankers but expose them to damaging runs. Authorities may not want to stand by and watch banks collapse. However, unconstrained direct bailouts undermine the disciplinary role of deposits. Moreover, competition forces banks to promise depositors more, increasing intervention and making the system worse off. By contrast, constrained central bank intervention to lower rates maintains private discipline, while offsetting contractual rigidity. It may still lead banks to make excessive liquidity promises. Anticipating this, central banks should raise rates in normal times to offset distortions from reducing rates in adverse times.

Loans are illiquid when a lender needs relationship-specific skills to collect them. Consequently, if the relationship lender needs funds before the loan matures, she may demand to liquidate early, or require a return premium, when she lends directly. Borrowers also risk losing funding. The costs of illiquidity are avoided if the relationship lender is a bank with a fragile capital structure, subject to runs. Fragility commits banks to creating liquidity, enabling depositors to withdraw when needed, while buffering borrowers from depositors' liquidity needs. Stabilization policies, such as capital requirements, narrow banking, and suspension of convertibility, may reduce liquidity creation.

This paper shows that bank deposit contracts can provide allocations superior to those of exchange markets, offering an explanation of how banks subject to runs can attract deposits. Investors face privately observed risks which lead to a demand for liquidity. Traditional demand deposit contracts which provide liquidity have multiple equilibria, one of which is a bank run. Bank runs in the model cause real economic damage, rather than simply reflecting other problems. Contracts which can prevent runs are studied, and the analysis shows that there are circumstances when government provision of deposit insurance can produce superior contracts.

We develop a theory of how corporate lending and financial intermediation change based on the fundamentals of the firm and its environment. We focus on the interaction between the prospective net worth or liquidity of an industry and the firm’s internal governance or pledgeability. Variations in prospective liquidity can induce changes in the nature, covenants, and quantity of loans that are made, the identity of the lender, and the extent to which the lender is leveraged. We offer predictions on how these might vary over the financial cycle.