An economic model of contagion in interbank lending markets

This paper considers the stability of a financial system in which heterogenous banks interact through a lending market. We analyse a discrete time model in which households and banks are located on a circular city. Households present banks with risky investment opportunities, which banks fund through deposits and interbank borrowing. In the event of bankruptcy, a bank defaults on its interbank loans potentially resulting in contagion and losses for other banks. Through simulation we examine the vulnerability of the financial system to systemic events, demonstrating the non-linear relationship between market concentration, shock severity and bankruptcies. The role and effect of regulatory actions such as reserve requirements, minimum bank capitalisation and constraints on the size of borrowing relationships, are considered in limiting these effects.Systemic risk; Interbank lending; Regulation; Network; Heterogeneity

Evaluation of macroeconomic models for financial stability analysis

As financial stability has gained focus in economic policymaking, the demand for analyses of financial stability and the consequences of economic policy has increased. Alternative macroeconomic models are available for policy analyses, and this paper evaluates the usefulness of some models from the perspective of financial stability. Financial stability analyses are complicated by the lack of a clear and consensus definition of ‘financial stability’, and the paper concludes that operational definitions of this term must be expected to vary across alternative models. Furthermore, since assessment of financial stability in general is based on a wide range of risk factors, one can not expect one single model to satisfactorily capture all the risk factors. Rather, a suite of models is needed. This is in particular true for the evaluation of risk factors originating and developing inside and outside the financial system respectively.Financial stability; Banks; Default; Macroeconomic models; Policy

Systemic risk: A survey

This paper develops a broad concept of systemic risk, the basic economic concept for the understanding of financial crises. It is claimed that any such concept must integrate systemic events in banking and financial markets as well as in the related payment and settlement systems. At the heart of systemic risk are contagion effects, various forms of external effects. The concept also includes simultaneous financial instabilities following aggregate shocks. The quantitative literature on systemic risk, which was evolving swiftly in the last couple of years, is surveyed in the light of this concept. Various rigorous models of bank and payment system contagion have now been developed, although a general theoretical paradigm is still missing. Direct econometric tests of bank contagion effects seem to be mainly limited to the United States. Empirical studies of systemic risk in foreign exchange and security settlement systems appear to be non-existent. Moreover, the literature surveyed reflects the general difficulty to develop empirical tests that can make a clear distinction between contagion in the proper sense and joint crises caused by common shocks, rational revisions of depositor or investor expectations when information is asymmetric ('information-based' contagion) and 'pure' contagion as well as between 'efficient' and 'inefficient' systemic events. JEL Classification: G21, G29, G12, E49banking crises, Contagion, currency crises, financial markets, financial stability, payment and settlement systems, systemic risk

Bank liquidity and financial stability.

Fluctuations in investor risk aversion are often cited as a factor explaining crises on financial markets. The alternation between periods of bullishness prompting investors to make risky investments, and periods of bearishness, when they retreat to the safest forms of investments, could be at the root of sharp fluctuations in asset prices. One problem in the assessment of these different periods is clearly distinguishing the risk perceived by agents from risk aversion itself. There are several types of risk aversion indicators used by financial institutions (the VIX, the LCVI, the GRAI, etc.). These indices, which are estimated in diverse ways, often show differing developments, although it is not possible to directly assess which is the most accurate. An interesting method in this respect is to link the indicators to financial crises. In principle, financial crises should coincide with periods in which risk aversion increases. Here we estimate probabilities of financial crises –currency and stock market crises– using the different risk aversion indicators as explanatory variables. This allows us to assess their respective predictive powers. The tests carried out show that risk aversion does tend to increase before crises, at least when it is measured by the most relevant indices. This variable is a good leading indicator of stock market crises, but is less so for currency crises.

Financial market liquidity and the lender of last resort.

In the summer 2007, difficulties in the US subprime mortgage markets have led to disruptive developments in many financial market segments, in particular in interbank money markets, where central banks in the US and in Europe repeatedly intervened to restore smooth market functioning. This article investigates the circumstances in which liquidity shortages may appear in fi nancial markets and evaluates a number of options available to the lender of last resort wishing to restore fi nancial stability. It also suggests that the consideration of balance sheet data is not sufficient for evaluating the risks of leveraged financial entities. Instead, the analysis calls for an explicit consideration of collateral pledges, market illiquidity, and potential non-availability of market prices. Our main messages can be summarised as follows. First, we provide a clear hierarchy across policy alternatives. Taking a risk-efficiency perspective, it turns out that targeted liquidity assistance is preferable to market-wide non-discriminatory liquidity injections. In particular, when liquidity may be alternatively used for speculative purposes during the crisis, non-discriminating open market operations may attract unfunded market participants that divert funding resources away from its best uses in the financial sector. As a consequence, targeted liquidity assistance may become strictly superior. Second, we suggest that forced asset sales may lead to disruptive market developments in a context where financial investors are highly leveraged. Assuming away external funding or renegociability of debt contracts, a fully leveraged investor hit by a liquidity shock would have to liquidate some assets. When markets are not perfectly liquid, asset liquidation depresses market prices. Under standard risk management constraints, lower prices induce a re-evaluation of marked-to-market balance sheets, provoke margin calls, and trigger further selling. In the worst scenario, the leveraged investor may not be able to face the sum of liquidity outfl ows and subsequent margin calls. In that case, the market for illiquid assets breaks down, rendering the valuation of such assets an ambiguous exercise. For investors, such potential trading disruptions imply that the loss that triggers operational default is likely to be much smaller than suggested by standard risk measures.

Evaluation of macroeconomic models for financial stability analysis

As financial stability has gained focus in economic policymaking, the demand for analyses of financial stability and the consequences of economic policy has increased. Alternative macroeconomic models are available for policy analyses, and this paper evaluates the usefulness of some models from the perspective of financial stability. Financial stability analyses are complicated by the lack of a clear and consensus definition of ‘financial stability’, and the paper concludes that operational definitions of this term must be expected to vary across alternative models. Furthermore, since assessment of financial stability in general is based on a wide range of risk factors, one can not expect one single model to satisfactorily capture all the risk factors. Rather, a suite of models is needed. This is in particular true for the evaluation of risk factors originating and developing inside and outside the financial system respectively.Financial stability; Banks; Default; Macroeconomic models; Policy

Contagion and risk-sharing on the inter-bank market

Increasing inter-bank lending has an ambiguous impact on financial stability. Two opposing effects have been identified: promoting stability through risk sharing and providing a channel through which contagion may spread. In this paper we identify the conditions under which each relationship holds. In response to large economy-wide shocks, greater numbers of inter-bank lending relationships are shown to worsen systemic events, however, for smaller shocks the opposite effect is observed. As such there is no optimal inter-bank market structure which maximizes stability under all conditions. In contrast, deposit insurance costs are always reduced under greater numbers of inter-bank lending relationships.Keywords: Systemic risk, Inter-bank lending, Contagion, Regulation, Network

The Role of Capital in Financial Institutions

This paper examines the role of capital in financial institutions. As the introductory article to a conference on the role of capital management in banking and insurance, it describes the authors' views of why capital is important, how market-generated capital requirements' differ from regulatory requirements and the form that regulatory requirements should take. It also examines the historical trends in bank capital, problems in measuring capital and some possible unintended consequences of capital requirements. According to the authors, the point of departure for all modern research on capital structure is the Modigliani-Miller (M&M, 1958) proposition that in a frictionless world of full information and complete markets, a firm s capital structure cannot affect its value. The authors suggest however, that financial institutions lack any plausible rationale in the frictionless world of M&M. Most of the past research on financial institutions has begun with a set of assumed imperfections, such as taxes, costs of financial distress, transactions costs, asymmetric information and regulation. Miller argues (1995) that these imperfections may not be important enough to overturn the M&M Proposition. Most of the other papers presented at this conference on capital take the view that the deviations from M&M s frictionless world are important, so that financial institutions may be able to enhance their market values by taking on an optimal amount of leverage. The authors highlight these positions in this article. The authors next examine why markets require' financial institutions to hold capital. They define this capital requirement' as the capital ratio that maximizes the value of the bank in the absence of regulatory capital requirements and all the regulatory mechanisms that are used to enforce them, but in the presence of the rest of the regulatory structure that protects the safety and soundness of banks. While the requirement differs for each bank, it is the ratio toward which each bank would tend to move in the long run in the absence of regulatory capital requirements. The authors then introduce imperfections into the frictionless world of M&M taxes and the costs of financial distress, transactions costs and asymmetric information problems and the regulatory safety net. The authors analysis suggests that departures from the frictionless M&M world may help explain market capital requirements for banks. Tax considerations tend to reduce market capital requirements , the expected costs of financial distress tend to raise these requirements , and transactions costs and asymmetric information problems may either increase or reduce the capital held in equilibrium. The federal safety net shields bank creditors from the full consequences of bank risk taking and thus tends to reduce market capital requirements . The paper then summarizes the historical evolution of bank capital ratios in the United States and the reasons regulators require financial institutions to hold capital. They suggest that regulatory capital requirements are blunt standards that respond only minimally to perceived differences in risk rather than the continuous prices and quantity limits set by uninsured creditors in response to changing perceptions of the risk of individual banks. The authors suggest an ideal system for setting capital standards but agree that it would be prohibitively expensive, if not impossible. Regulators lack precise estimates of social costs and benefits to tailor a capital requirement for each bank, and they cannot easily revise the requirements continuously as conditions change. The authors continue with suggestions for measuring regulatory capital more effectively. They suggest that a simple risk-based capital ratio is a relatively blunt tool for controlling bank risk-taking. The capital in the numerator may not always control bank moral hazard incentive; it is difficult to measure, and its measured value may be subject to manipulation by gains trading . The risk exposure in the denominator is also difficult to measure, corresponds only weakly to actual risk and may be subject to significant manipulation. These imprecisions worsen the social tradeoff between the externalities from bank failures and the quantity of bank intermediation. To keep bank risk to a tolerable level, capital standards must be higher on average than they otherwise would be if the capital ratios could be set more precisely, raising bank costs and reducing the amount of intermediation in the economy in the long run. Since actual capital standards are, at best, an approximation to the ideal, the authors argue that it should not be surprising that they may have had some unintended effects. They examine two unintended effects on bank portfolio risk or credit allocative inefficiencies. These two are the explosive growth of securitization and the so-called credit crunch by U.S. banks in the early 1990s. The authors show that capital requirements may give incentives for some banks to increase their risks of failure. Inaccuracies in setting capital requirements distort relative prices and may create allocative inefficiencies that divert financial resources from their most productive uses. During the 1980s, capital requirements may have created artificial incentives for banks to take off-balance sheet risk, and changes in capital requirements in the 1990s may have contributed to a credit crunch.

Open-end real estate funds in Germany: genesis and crisis

Open-end real estate funds are of particular importance in the German bank- dominated financial system. However, recently the German open-end fund industry came under severe distress which triggered a broad discussion of required regulatory interventions. This paper gives a detailed description of the institutional structure of these funds and of the events that led to the crisis. Furthermore, it applies recent banking theory to openend real estate funds in order to understand why the open-end fund structure was so prevalent in Germany. Based on these theoretical insights we evaluate the various policy recommendations that have been raised. --Open-End Funds,Liquidity Transformation,Liquidity Crisis,Risk Sharing