Douglas W. Diamond

Bank Runs, Deposit Insurance, and Liquidity

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.

Financial Intermediation and Delegated Monitoring

This paper develops a theory of financial intermediation based on minimizing the cost of monitoring information which is useful for resolving incentive problems between borrowers and lenders. It presents a characterization of the costs of providing incentives for delegated monitoring by a financial intermediary. Diversification within an intermediary serves to reduce these costs, even in a risk neutral economy. The paper presents some more general analysis of the effect of diversification on resolving incentive problems. In the environment assumed in the model, debt contracts with costly bankruptcy are shown to be optimal. The analysis has implications for the portfolio structure and capital structure of intermediaries.

Monitoring and Reputation: The Choice between Bank Loans and Directly Placed Debt

This paper determines when a debt contract will be monitored by lenders. This is the choice between borrowing directly (issuing a bond, without monitoring) and borrowing through a bank that monitors to alleviate moral hazard. This provides a theory of bank loan demand and of the role of monitoring in circumstances in which reputation effects are important. A key result is that borrowers with credit ratings toward the middle of the spectrum rely on bank loans, and in periods of high interest rates or low future profitability, higher-rated borrowers choose to borrow from banks.

Constraints on short-selling and asset price adjustment to private information

This paper models effects of short-sale constraints on the speed of adjustment (to private information) of security prices. Constraints eliminate some informative trades, but do not bias prices upward. Prohibiting traders from shorting reduces the adjustment speed of prices to private information, especially to bad news. Non-prohibitive costs can have the reverse effect, but this is unlikely. Implications are developed about return distributions on information announcement dates. Periods of inactive trade are shown to impart a downward bias to measured returns. An unexpected increase in the short-interest of a stock is shown to be bad news.

Reputation Acquisition in Debt Markets

This paper studies reputation formation and the evolution over time of the incentive effects of reputation to mitigate conflicts of interest between borrowers and lenders. Borrowers use the proceeds of their loans to fund projects. In the absence of reputation effects, borrowers have incentives to select excessively risky projects. If there is sufficient adverse selection, reputation will not initially provide improved incentives to borrowers with short credit histories. Over time, if a good reputation is acquired, reputation will provide improved incentives. General characteristics of markets in which reputation takes time to work are identified.

Seniority and maturity of debt contracts

Abstract This paper provides a model of how borrowers with private information about their credit prospects choose seniority and maturity of debt. Increased short-term debt leads lenders to liquidate too often. It also increases the sensitivity of financing costs to new information, although better-than-average borrowers desire information sensitivity. The model implies that short-term debt will be senior to long-term debt, and that long-term debt will allow the issue of additional future senior debt. The model also has implications on the structure of leveraged buyouts and on how various types of lenders respond to potential defaults.

Liquidity Shortages and Banking Crises

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.

Information aggregation in a noisy rational expectations economy

Abstract This paper analyzes a general equilibrium model of a competitive security market in which traders possess independent pieces of information about the return of a risky asset. Each trader conditions his estimate of the return both on his own private source of information and price, which in equilibrium serves as a ‘noisy’ aggregator of the total information observed by all traders. A closed-form characterization of the rational expectations equilibrium is presented. A counter-example to the existence of ‘fully revealing’ equilibrium is developed.

Liquidity, Banks, and Markets

This paper examines the roles of markets and banks when both are active, characterizing the effects of financial market development on the structure and market share of banks. Banks lower the cost of giving investors rapid access to their capital and improve the liquidity of markets by diverting demand for liquidity from markets. Increased participation in markets causes the banking sector to shrink, primarily through reduced holdings of long‐term assets. In addition, increased participation leads to longer‐maturity real and financial assets and a smaller gap between the maturity of financial and real assets.

Banks, Short Term Debt and Financial Crises: Theory, Policy Implications and Applications

Short-term borrowing has often been blamed for precipitating financial crises. We argue that while the empirical association between a financial institutions, or countrys, short-term borrowing and susceptibility to crises may, in fact, exist, the direction of causality is often precisely the opposite to the one traditionally suggested by commentators. Institutions like banks that want to enhance their ability to provide liquidity and credit to difficult borrowers have to borrow short-term. Similarly countries that have poor disclosure rules and inadequate investor protections, have limited long-term debt capacity, and will find their borrowing becoming increasingly short-term as they finance illiquid investment. Thus it is the increasing illiquidity of the investment being financed (or the deteriorating credit quality of borrowers) that necessitates short-term financing, and causes the susceptibility to crises. In fact, once illiquid investments have been financed, rather than making the system more stable, a ban on short-term financing may precipitate a more severe crisis. Even a priori, a ban is not without adverse consequences policy makers have to trade off the costs of decreased credit creation and investment against the benefits of greater stability. A ban on short-term debt often deals with symptoms rather than underlying causes.