Portfolio Diversification Leverage And Financial Contagion

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.

Inhaltsangabe:Abstract: In recent years academics and policy makers have become more and more interested in the phenomenon of contagion, a concept involving the transmission of a financial crisis from one country to one or more other countries. During the 1990s world capital markets witnessed a number of financial crises. In 1992 the Exchange Rate Mechanism (ERM) crisis hit the European continent. Several countries in Latin America have been rocked during the 1994-95 Tequila crisis, and the Asian Flu spread through East Asian countries in 1997-98 with dramatic social implications. Later in 1998 the famous hedge fund Long Term Capital Management (LTCM) had to file for bankruptcy and the Russian debt failure shocked international capital markets and increased volatility on a global scale. The crisis spread to as far as Brazil in early 1999 and developed markets have become victims as well. The question asked by academics and policy makers is how countries should behave in order to avoid contagion. To answer this question it is necessary to understand the different channels of contagion in greater detail and how a crisis can be transmitted from one country to another. The objective of this paper is to highlight those channels and to present a number of models and theories of contagion, which have recently been developed by academics. In general, there are several strands of theories in the literature that try to explain the transmission of crises. During the mid and late 1990s fundamental-based contagion and spillovers became popular among researchers and policy makers. Furthermore, financial linkages have been known to contribute to contagion. In contrast, in recent years, portfolio flows of international investors moved into the focus of academics. The advocates of fundamental-based contagion and spillovers argue that trade linkages between countries are responsible for contagion. For instance, a devaluation of a country's currency may lead to a negative change in fundamentals of its trading partners. On the other hand, contagion due to financial linkages is mainly explained by the fact that countries share the same banks and therefore have common creditors. A crisis in one country then leads to a deteriorating balance sheet of those common creditors. This in turn may force banks to withdraw money out of other countries in order to avoid further losses, a fact that leads to contagious sellouts. The role of international portfolio flows, which is [...]

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.

This paper analyzes portfolio diversification, leverage, and financial contagion. It studies the extent to which basic principles of portfolio diversification explain “contagious selling” of financial assets when there are purely local shocks. The paper demonstrates that the elementary portfolio theory offers key insights into “contagion.” Most important, portfolio diversification and leverage are sufficient to explain why an investor will find it optimal to significantly reduce all risky asset positions when an adverse shock impacts just one asset.

This paper provides an overview of the recent theoretical and empirical research on herd behavior in financial markets. It looks at what precisely is meant by herding, the causes of herd behavior, the success of existing studies in identifying the phenomenon, and the effect that herding has on financial markets. The paper also surveys a selected number of studies that evaluated the demand for money using the error-correction model approach in the 1990s across a range of industrial and developing countries.

What can the international community do to prevent financial contagion?

This book focuses on optimal control and systems engineering in the big data era. It examines the scientific innovations in optimization, control and resilience management that can be applied to further success. In both business operations and engineering applications, there are huge amounts of data that can overwhelm computing resources of large-scale systems. This “big data” provides new opportunities to improve decision making and addresses risk for individuals as well in organizations. While utilizing data smartly can enhance decision making, how to use and incorporate data into the decision making framework remains a challenging topic. Ultimately the chapters in this book present new models and frameworks to help overcome this obstacle. Optimization and Control for Systems in the Big-Data Era: Theory and Applications is divided into five parts. Part I offers reviews on optimization and control theories, and Part II examines the optimization and control applications. Part III provides novel insights and new findings in the area of financial optimization analysis. The chapters in Part IV deal with operations analysis, covering flow-shop operations and quick response systems. The book concludes with final remarks and a look to the future of big data related optimization and control problems.