Over the past 40 years, U.S. capital markets have grown much faster than banks, so that banks’ share of credit to the private nonfinancial sector has dropped from 55% to 34% (see BIS statistics here). Nevertheless, banks remain a critical part of the financial system. They operate the payments system, supply credit, and serve as agents and catalysts for a wide range of other financial transactions. As a result, their well-being remains a key concern. A resilient banking system is, above all, one that has sufficient capital to weather the loan defaults and declines in asset values that will inevitably come.

In this primer, we explain the nature of bank capital, highlighting its role as a form of self-insurance providing both a buffer against unforeseen losses and an incentive to manage risk-taking. We describe some of the challenges in measuring capital and briefly discuss a range of approaches for setting capital requirements. While we do not know the optimal level of capital that banks (or other intermediaries) should be required to hold, we suggest a practical approach for setting requirements that would promote the safety of the financial system without diminishing its efficiency....

Free Riding in Finance: A Primer

Many features of our financial system—institutions like banks and insurance companies, as well as the configuration of securities markets—are a consequence of legal conventions (the rules about property rights and taxes) and the costs associated with obtaining and verifying information. When we teach money and banking, three concepts are key to understanding the structure of finance: adverse selection, moral hazard, and free riding. The first two arise from asymmetric information, either before (adverse selection) or after (moral hazard) making a financial arrangement (see our earlier primers here and here).

This primer is about the third concept: free riding. Free riding is tied to the concept of a public good, so we start there. Then, we offer three examples where free riding plays a key role in the organization of finance: credit ratings; schemes like the Madoff scandal; and efforts to secure financial stability more broadly....

Moral Hazard: A Primer

The term moral hazard originated in the insurance business. It was a reference to the need for insurers to assess the integrity of their customers. When modern economists got ahold of the term, the meaning changed. Instead of making judgments about a person’s character, the focus shifted to incentives. For example, a fire insurance policy might limit the motivation to install sprinklers while a generous automobile insurance policy might encourage reckless driving. Then there is Kenneth Arrow’s original example of moral hazard: health insurance fosters overtreatment by doctors. Employment arrangements suffer from moral hazard, too: will you shirk unpleasant tasks at work if you’re sure to receive your paycheck anyway?

Moral hazard arises when we cannot costlessly observe people’s actions and so cannot judge (without costly monitoring) whether a poor outcome reflects poor fortune or poor effort. Like its close relative, adverse selection, moral hazard arises because two parties to a transaction have different information. This information asymmetry manifests itself in two ways. Where adverse selection is about hidden attributes, affecting a transaction before it occurs, moral hazard is about hidden actions that have an impact after making an arrangement.

In this post, we provide a brief introduction to the concept of moral hazard, focusing on how various aspects of the financial system are designed to mitigate the challenges it causes....

Adverse Selection: A Primer

Information is the basis for our economic and financial decisions. As buyers, we collect information about products before entering into a transaction. As investors, the same goes for information about firms seeking our funds. This is information that sellers and fund-seeking firms typically have. But, when it is too difficult or too costly to collect information, markets function poorly or not at all.

Economists use the term adverse selection to describe the problem of distinguishing a good feature from a bad feature when one party to a transaction has more information than the other party. The degree of adverse selection depends on how costly it is for the uninformed actor to observe the hidden attributes of a product or counterparty. When key characteristics are sufficiently expensive to discern, adverse selection can make an otherwise healthy market disappear.

In this primer, we examine three examples of adverse selection: (1) used cars; (2) health insurance; and (3) private finance. We use these examples to highlight mechanisms for addressing the problem....

Primers

Money, Banking, and Financial Markets