A Factor-model Approach for Correlation Scenarios and Correlation Stress Testing
Natalie Packham, Fabian Wöbbeking
Journal of Banking and Finance,
April
2019
Abstract
In 2012, JPMorgan accumulated a USD 6.2 billion loss on a credit derivatives portfolio, the so-called “London Whale”, partly as a consequence of de-correlations of non-perfectly correlated positions that were supposed to hedge each other. Motivated by this case, we devise a factor model for correlations that allows for scenario-based stress testing of correlations. We derive a number of analytical results related to a portfolio of homogeneous assets. Using the concept of Mahalanobis distance, we show how to identify adverse scenarios of correlation risk. In addition, we demonstrate how correlation and volatility stress tests can be combined. As an example, we apply the factor-model approach to the “London Whale” portfolio and determine the value-at-risk impact from correlation changes. Since our findings are particularly relevant for large portfolios, where even small correlation changes can have a large impact, a further application would be to stress test portfolios of central counterparties, which are of systemically relevant size.
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The Dynamics of Bank Spreads and Financial Structure
Reint E. Gropp, Christoffer Kok, J.-D. Lichtenberger
Quarterly Journal of Finance,
Nr. 4,
2014
Abstract
This paper investigates the effect of within banking sector competition and competition from financial markets on the dynamics of the transmission from monetary policy rates to retail bank interest rates in the euro area. We use a new dataset that permits analysis for disaggregated bank products. Using a difference-in-difference approach, we test whether development of financial markets and financial innovation speed up the pass through. We find that more developed markets for equity and corporate bonds result in a faster pass-through for those retail bank products directly competing with these markets. More developed markets for securitized assets and for interest rate derivatives also speed up the transmission. Further, we find relatively strong effects of competition within the banking sector across two different measures of competition. Overall, the evidence supports the idea that developed financial markets and competitive banking systems increase the effectiveness of monetary policy.
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Initial Evidence from a New Database on Capital Market Restrictions
Makram El-Shagi
Panoeconomicus,
Nr. 3,
2012
Abstract
One of the key obstacles to the empirical analysis of capital controls has been the unavailability of a detailed set of indicators for controls that cover a broad set of countries over a range of years. In this paper, we propose a new set of indicators derived from the Annual Reports on Exchange Arrangements and Export Restrictions. Contrary to most earlier attempts to construct control indicators from this source, our set of indices allows one to analyze the control intensity separately for inflow, outflow and repatriation controls. An additional set of indicators features information on the institutional design of controls. At first glance, the data show that the financial crisis caused a surge in capital market restrictions, most notably concerning the derivatives market. This reflex, which is not justified by the scarce empirical evidence on the success of controls, shows the importance of having a valid measure to allow an econometrically sound policy evaluation in this field. The data are available from the author upon request.
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Protect and Survive? Did Capital Controls Help Shield Emerging Markets from the Crisis?
Makram El-Shagi
Economics Bulletin,
Nr. 1,
2012
Abstract
Using a new dataset on capital market regulation, we analyze whether capital controls helped protect emerging markets from the real economic consequences of the 2009 financial and economic crisis. The impact of the crisis is measured by the 2009 forecast error of a panel state space model, which analyzes the business cycle dynamics of 63 middle-income countries. We find that neither capital controls in general nor controls that were specifically targeted to derivatives (that played a crucial role during the crisis) helped shield economies. However, banking regulation that limits the exposure of banks to global risks has been highly successful.
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The Role of Investment Banking for the German Economy: Final Report for Deutsche Bank AG, Frankfurt/Main
Michael Schröder, M. Borell, Reint E. Gropp, Z. Iliewa, L. Jaroszek, G. Lang, S. Schmidt, K. Trela
ZEW-Dokumentationen, Nr. 12-01,
Nr. 1,
2011
Abstract
The aim of this study is to assess the contributions of investment banking to the economy with a particular focus on the German economy. To this end we analyse both the economic benefits and the costs stemming from investment banking.
The study focuses on investment banks as this part of banking is particularly relevant for financing companies as well as the development and use of specific products to support the needs of private and professional clients. The assessment of benefits and costs of investment banking has been conducted from a European perspective. Nevertheless there is a focus on the German economy to allow a more detailed analysis of certain aspects as for example the use of derivatives by German companies, the success of M&As in Germany or the effect of securitization on loan supply and GDP in Germany. For comparison purposes other European countries and also the U.S. have been taken into account.
The last financial crisis has shown the negative impacts of banks on the financial system and the whole economy. In a study on the contribution of investment banks to systemic risk we quantify the negative side of the investment banking business.
In the last part of the study we assess how the effects of regulatory changes on investment banking. All important changes in banking and capital market regulation are taken into account such as Basel III, additional capital requirements for systemically important financial institutions, regulation of OTC derivatives and specific taxes.
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