Time Consistency: A Primer

The problem of time consistency is one of the most profound in social science. With applications in areas ranging from economic policy to counterterrorism, it arises whenever the effectiveness of a policy today depends on the credibility of the commitment to implement that policy in the future.

For simplicity, we will define a time consistent policy as one where a future policymaker lacks the opportunity or the incentive to renege. Conversely, a policy lacks time consistency when a future policymaker has both the means and the motivation to break the commitment.

In this post, we describe the conceptual origins of time consistency. To emphasize its broad importance, we provide three economic examples—in monetary policy, prudential regulation, and tax policy—where the impact of the idea is especially notable....

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....

Labor's Declining Share: A Primer

Economists build models around simple facts to isolate what drives behavior. In macroeconomics, perhaps the most famous of these facts has been the observed stability of the shares of income paid to labor and to capital. At least since Kaldor wrote 60 years ago, this pattern of income distribution has been at the top of the list of regularities to be explained by theories of economic growth.

Well, it turns out that what was stable for much of the 20th century looks as if it is unstable in the 21st. For at least the past 15 years, and possibly for several decades, labor’s share of national income has been declining and capital’s share has been rising in most advanced and many emerging economies.

It is important that we understand why labor's share has declined, and whether that decline will continue. The answer could influence a range of policies, from education and training to taxation and transfers. In what follows, we describe what we know about the evolution of labor's share (including key measurement issues) and highlight several explanations of the observed decline that have recently been proposed.

The Phillips Curve: A Primer

Economists have debated the relationship between inflation and unemployment at least since A.W. Phillips’s study of U.K. data from 1861 to 1957 was published 60 years ago. The idea that a tight or slack labor market should result in faster or slower wage gains seems like a natural corollary to standard economic thinking about how prices respond to deviations of demand from supply. But, over the years, disputes about this Phillips curve relationship have been and remain fierce.

As the U.S. labor market tightens, and unemployment approaches levels we have not seen in more than 15 years, the question is whether inflation is going to make a comeback. More broadly, how useful is the Phillips curve as a guide for Federal Reserve policymakers who wish to achieve a 2-percent inflation target over the long run?

To anticipate our conclusion, despite evidence of a negative relationship between wage inflation and unemployment, central banks ought not rely on a stable Phillips curve for setting monetary policy.

GDP-linked Bonds: A Primer

Gross government debt in advanced economies has surpassed 105% of GDP, up from less than 75% a decade ago. Some countries with especially large debts—including Greece (177%), Italy (133%) and Portugal (129%)—are viewed not only as a risk to the countries themselves, but to others as well. As a result, policymakers and economists have been looking for ways to make it easier to manage these heavier debt burdens.

One prominent suggestion is that countries should issue GDP-linked bonds that tie the size of debt payments to their economy's well-being. We find this idea attractive, and see the expanding discussion of the viability of GDP-linked bonds both warranted and useful (see here and here). However, the practical issues associated with GDP data revision remain a formidable obstacle to the broad issuance and acceptance of these instruments....

A Primer on Securities Lending

Securities lending (SL) is one of the less-well-publicized shadow banking activities. Like repurchase agreements (repo) and asset-backed commercial paper, SL can be a source of very short-term wholesale funding, allowing a shadow bank to engage in the kind of liquidity, maturity and credit transformation that banks do. And, like other short-term funding sources, it can suddenly dry up, making it a source of systemic risk. When funding evaporates, fire sales and a credit crunch follow.

Indeed, SL played a supporting role in the 2007-09 financial crisis, being partly responsible for the collapse of the large insurance company AIG when the market seized in September 2008 (see chart). While SL has not garnered the attention of capital and liquidity regulation or central clearing, or even repo markets, it is still worth understanding what securities lending is and the risks it poses. That is the purpose of this post...

A Primer on Helicopter Money

Helicopter money is not monetary policy. It is a fiscal policy carried out with the cooperation of the central bank. That is, if the Fed were to drop $100 bills out of helicopters, it would be doing the Treasury’s bidding.

We are wary of joining the cacophony of commentators on helicopter money, but our sense is that the discussion could use a bit of structure...

A Primer on Central Bank Independence

Central bank independence is controversial. It requires the delegation of powerful authority to a group of unelected officials. In a democracy, this anomaly naturally raises questions of legitimacy. It also raises fears of the concentration of power in the hands of a select few.

An independent central bank is a device to overcome the problem of time consistency: the concern that policymakers will renege in the future on a policy promise made today ....

Primers

Money, Banking, and Financial Markets