Understanding Bank Capital: A Primer

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....

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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....

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Resolution Regimes for Central Clearing Parties

Clean water and electric power are essential for modern life. In the same way, the financial infrastructure is the foundation for our economic system. Most of us take all three of these, water, electricity and finance, for granted, assuming they will operate through thick and thin.

As engineers know well, a system’s resilience depends critically on the design of its infrastructure. Recently, we discussed the chaos created by the October 1987 stock market crash, noting the problems associated with the mechanisms for trading and clearing of derivatives. Here, we take off where that discussion left off and elaborate on the challenge of designing a safe derivatives trading system―safe, that is, in the sense that it does not contribute to systemic risk.

Today’s infrastructure is significantly different from that of 1987. In the aftermath of the 2007-09 financial crisis, authorities in the advanced economies committed to overhaul over-the-counter (OTC) derivatives markets. The goal is to replace bilateral OTC trading with a central clearing party (CCP) that is the buyer to every seller and the seller to every buyer....

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Looking Back: The Financial Crisis Began 10 Years Ago This Week

In his memorable review of 21 books about the 2007-09 financial crisis, Andrew Lo evoked Kurosawa’s classic film, Rashomon, to characterize the remarkable differences between these crisis accounts. Not only were the interpretations in dispute, but the facts were as well: “Even its starting date is unclear. Should we mark its beginning at the crest of the U.S. housing bubble in mid-2006, or with the liquidity crunch in the shadow banking system in late 2007, or with the bankruptcy filing of Lehman Brothers and the ‘breaking of the buck’ by the Reserve Primary Fund in September 2008?”

In our view, the crisis began in earnest 10 years ago this week. On August 9, 2007, BNP Paribas announced that, because their fund managers could not value the assets in three mutual funds, they were suspending redemptions. With a decade’s worth of hindsight, we view this as a propitious moment to review both the precursors and the start of the worst financial crisis since the Great Depression of the 1930s.

But, first things first: What is a financial crisis? In our view, the term refers to a sudden, unanticipated shift from a reasonably healthy equilibrium—characterized by highly liquid financial markets, low risk premia, easily available credit, and low asset price volatility—to a very unhealthy one with precisely the opposite features. We use the term “equilibrium” to reflect a persistent state of financial conditions and note that—as was the case for Humpty Dumpty—it is easy to shift from a good financial state to a bad one, but very difficult to shift back again....

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The Scandal is What's Legal

If you haven’t seen The Big Short, you should. The acting is superb and the story enlightening: a few brilliant outcasts each discover just how big the holes are that eventually bury the U.S. financial system in the crisis of 2007-2009. If you’re like most people we know, you’ll walk away delighted by the movie and disturbed by the reality it captures. [Full disclosure: one of us joined a panel organized by the film’s economic consultant to view and discuss it with the director.]

But we're not film critics, The moviealong with some misleading criticismprompts us to clarify what we view as the prime causes of the financial crisis. The financial corruption depicted in the movie is deeply troubling (we've written about fraud and conflicts of interest in finance here and here). But what made the U.S. financial system so fragile a decade ago, and what made the crisis so deep, were practices that were completely legal. The scandal is that we still haven't addressed these properly....


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