Contagion in a Financial System

Financial contagion is often observed in recent financial crisis, which illustrates a critical need for new and fundamental understanding of its dynamics. So in this paper we mainly focus on modeling and analysing the financial contagion in a system where a large number of financial institutions are randomly connected by the direct balance sheets linkages own to the lending or borrowing relationships. We propose a simple contagion algorithm to study the effect of several determinants, such as the topology of financial network, exposure ratio, leverage ratio, and the liquidation ratio. One of our finding is that the financial contagion is weaker as the growth of connectivity of network, so a financial system with a higher connectivity is more stability or robustness; we also find that the exposure ratio increases the risk of financial contagion, but both the leverage ratio and liquidation ratio has a negative relationship on financial contagion

Origins and Resolution of Financial Crises; Lessons from the Current and Northern European Crises

Since July 2007 the world economy has experienced a severe financial crisis originating in the U.S. housing market. The crisis has subsequently spread to the financial sectors in European and Asian economies and led to a severe worldwide recession. The existing literature on financial crises rarely distinguish between factors that create the original strain on the financial sector and factors that explain why these strains lead to system-wide contagion and a possible credit crunch. Most of the literature on financial crises refers to factors that cause an original disruption in the financial system. We argue that a financial crisis with its contagion within the system is caused by failures of legal, regulatory and political institutions. One policy implication of our view is that the need for various forms of rescues of financial firms in times of crises would be reduced if appropriate institutions could be put in place Lacking appropriate institutions to avoid contagion within the financial system and a potential credit crunch, ad hoc financial crisis management is required. We draw on experiences from the financial crises in the Nordic countries at the end of the 1980s and the beginning of the 1990s. In particular, the Swedish model for crisis resolution, which has received attention during the current crisis, is discussed in order to illustrate the problems policy makers face in a financial crisis without appropriate institutions. Current European Union approaches to the crisis are discussed before turning to policy implications from an emerging market perspective in the current crisis.Financial Crisis; Institutional Failure; Insolvency Procedures; Contagion; Systemic Effects; Macroeconomic Shock; Financial Crisis Management; Swedish Model

Derivatives and Credit Contagion in Interconnected Networks

The importance of adequately modeling credit risk has once again been highlighted in the recent financial crisis. Defaults tend to cluster around times of economic stress due to poor macro-economic conditions, {\em but also} by directly triggering each other through contagion. Although credit default swaps have radically altered the dynamics of contagion for more than a decade, models quantifying their impact on systemic risk are still missing. Here, we examine contagion through credit default swaps in a stylized economic network of corporates and financial institutions. We analyse such a system using a stochastic setting, which allows us to exploit limit theorems to exactly solve the contagion dynamics for the entire system. Our analysis shows that, by creating additional contagion channels, CDS can actually lead to greater instability of the entire network in times of economic stress. This is particularly pronounced when CDS are used by banks to expand their loan books (arguing that CDS would offload the additional risks from their balance sheets). Thus, even with complete hedging through CDS, a significant loan book expansion can lead to considerably enhanced probabilities for the occurrence of very large losses and very high default rates in the system. Our approach adds a new dimension to research on credit contagion, and could feed into a rational underpinning of an improved regulatory framework for credit derivatives.Comment: 26 pages, 7 multi-part figure

A Network Model of Super-systemic Crises

Although the financial systems of advanced countries have weathered numerous shocks in recent years, the events triggered by the sub-prime crisis of August 2007 have been “super-systemic” in scope, enveloping financial institutions across the major economies as well as far away Iceland and New Zealand. In this paper, we apply network techniques to develop a framework for analyzing financial contagion that isolate the probability of contagion from its potential spread. Our results suggest that complex financial systems may be robust-yet-fragile in nature. Under plausible assumptions, the greater connectivity implied by new financial instruments (e.g., credit derivatives) reduces the likelihood of contagion. But the impact on the financial system, in the event of problems, can be on a significantly larger scale than before.

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

Stability analysis of financial contagion due to overlapping portfolios

Common asset holdings are widely believed to have been the primary vector of contagion in the recent financial crisis. We develop a network approach to the amplification of financial contagion due to the combination of overlapping portfolios and leverage, and we show how it can be understood in terms of a generalized branching process. By studying a stylized model we estimate the circumstances under which systemic instabilities are likely to occur as a function of parameters such as leverage, market crowding, diversification, and market impact. Although diversification may be good for individual institutions, it can create dangerous systemic effects, and as a result financial contagion gets worse with too much diversification. Under our model there is a critical threshold for leverage; below it financial networks are always stable, and above it the unstable region grows as leverage increases. The financial system exhibits "robust yet fragile" behavior, with regions of the parameter space where contagion is rare but catastrophic whenever it occurs. Our model and methods of analysis can be calibrated to real data and provide simple yet powerful tools for macroprudential stress testing.Comment: 25 pages, 8 figure

The Formation of Financial Networks

Modern banking systems are highly interconnected. Despite their various benefits, the linkages that exist between banks carry the risk of contagion. In this paper we investigate how banks decide on direct balance sheet linkages and the implications for contagion risk. In particular, we model a network formation process in the banking system. Banks form links order to reduce the risk of contagion. The network is formed endogenously and serves as an insurance mechanism. We show that banks manage to form networks that are resilient to contagion. Thus, in an equilibrium network, the probability of contagion is virtually 0.Financial Stability, Network Formation, Contagion Risk

Determinants of Banking System Fragility: A Regional Perspective

Abstract: Banking systems are fragile not only within one country but also within and across regions. We study the role of regional banking system characteristics for regional banking system fragility. We find that regional banking system fragility reduces when banks in the region jointly hold more liquid assets, are better capitalized, and when regional banking systems are more competitive. For Asia and Latin-America, a greater presence of foreign banks also reduces regional banking fragility. We further investigate the possibility of contagion within and across regions. Within region banking contagion is important in all regions but it is substantially lower in the developed regions compared to emerging market regions. For cross-regional contagion, we find that the contagion effects of Europe and the US on Asia and Latin America are significantly higher compared to the effect of Asia and Latin America among themselves. Finally, the impact of cross-regional contagion is attenuated when the host region has a more liquid and more capitalized banking sector.Banking system stability;cross-regional contagion;financial integration