Models of “contagion” rely on market imperfections to explain why adverse shocks in one asset market might be associated with asset sales in many unrelated markets. This paper demonstrates that contagion can be explained with basic portfolio theory without recourse to market imperfections. It also demonstrates that “Value-at-Risk” portfolio management rules do not have significantly different consequences for portfolio rebalancing and contagion than other rules. The paper’s main conclusion is that portfolio diversification and leverage may be sufficient to explain why investors would find it optimal to sell many higher-risk assets when a shock to one asset occurs.

No sooner had the Asian crisis broken out in 1997 than the witch-hunt started. With great indignation every Asian economy pointed fingers. They were innocent bystanders. The fundamental reason for the crisis was this or that - most prominently contagion - but also the decline in exports of the new commodities (high-tech goods), the steep rise of the dollar, speculators, etc. The prominent question, of course, is whether contagion could really have been the key factor and, if so, what are the channels and mechanisms through which it operated in such a powerful manner. The question is obvious because until 1997, Asia's economies were generally believed to be immensely successful, stable and well managed. This question is of great importance not only in understanding just what happened, but also in shaping policies. In a world of pure contagion, i.e. when innocent bystanders are caught up and trampled by events not of their making and when consequences go far beyond ordinary international shocks, countries will need to look for better protective policies in the future. In such a world, the international financial system will need to change in order to offer better preventive and reactive policy measures to help avoid, or at least contain, financial crises.

What can the international community do to prevent financial contagion?

This paper presents a novel approach to investigate and model the network of euro area banks’ large exposures within the global banking system. Drawing on a unique dataset, the paper documents the degree of interconnectedness and systemic risk of the euro area banking system based on bilateral linkages. We develop a Contagion Mapping model fully calibrated with bank-level data to study the contagion potential of an exogenous shock via credit and funding risks. We find that tipping points shifting the euro area banking system from a less vulnerable state to a highly vulnerable state are a non-linear function of the combination of network structures and bank-specific characteristics.

The Financial Crisis Inquiry Report, published by the U.S. Government and the Financial Crisis Inquiry Commission in early 2011, is the official government report on the United States financial collapse and the review of major financial institutions that bankrupted and failed, or would have without help from the government. The commission and the report were implemented after Congress passed an act in 2009 to review and prevent fraudulent activity. The report details, among other things, the periods before, during, and after the crisis, what led up to it, and analyses of subprime mortgage lending, credit expansion and banking policies, the collapse of companies like Fannie Mae and Freddie Mac, and the federal bailouts of Lehman and AIG. It also discusses the aftermath of the fallout and our current state. This report should be of interest to anyone concerned about the financial situation in the U.S. and around the world.THE FINANCIAL CRISIS INQUIRY COMMISSION is an independent, bi-partisan, government-appointed panel of 10 people that was created to "examine the causes, domestic and global, of the current financial and economic crisis in the United States." It was established as part of the Fraud Enforcement and Recovery Act of 2009. The commission consisted of private citizens with expertise in economics and finance, banking, housing, market regulation, and consumer protection. They examined and reported on "the collapse of major financial institutions that failed or would have failed if not for exceptional assistance from the government."News Dissector DANNY SCHECHTER is a journalist, blogger and filmmaker. He has been reporting on economic crises since the 1980's when he was with ABC News. His film In Debt We Trust warned of the economic meltdown in 2006. He has since written three books on the subject including Plunder: Investigating Our Economic Calamity (Cosimo Books, 2008), and The Crime Of Our Time: Why Wall Street Is Not Too Big to Jail (Disinfo Books, 2011), a companion to his latest film Plunder The Crime Of Our Time. He can be reached online at www.newsdissector.com.

This paper reviews the literature on financial crises focusing on three specific aspects. First, what are the main factors explaining financial crises? Since many theories on the sources of financial crises highlight the importance of sharp fluctuations in asset and credit markets, the paper briefly reviews theoretical and empirical studies on developments in these markets around financial crises. Second, what are the major types of financial crises? The paper focuses on the main theoretical and empirical explanations of four types of financial crises—currency crises, sudden stops, debt crises, and banking crises—and presents a survey of the literature that attempts to identify these episodes. Third, what are the real and financial sector implications of crises? The paper briefly reviews the short- and medium-run implications of crises for the real economy and financial sector. It concludes with a summary of the main lessons from the literature and future research directions.