JFRM  Vol.5 No.4 , December 2016
Credit Name Concentration Risk: Granularity Adjustment Approximation
Abstract: During the last subprime mortgage crisis, the concentration risk issue has become increasingly important in the world of finance. This risk is defined as the loss that we can incur from a large exposition of a single name counterparty, a sector or a product. This paper represents some mathematical models for assessment and quantification of the concentration risk under the Add-On approach. This study is based on the Granularity Adjustment (GA). This measure quantifies the idiosyncratic risk that is neglected by the Asymptotic Single Risk Factor model (ASRF) based on the infinitely granular assumption of the portfolio. This work is about the approximation of this measurement to simplify the formula of GA using the Ad-Hoc approach. We have implemented empirical tests to find the relation between the GA and concentration indexes and we applied these results to the iBoxx portfolio.
Cite this paper: Slime, B. (2016) Credit Name Concentration Risk: Granularity Adjustment Approximation. Journal of Financial Risk Management, 5, 246-263. doi: 10.4236/jfrm.2016.54023.

[1]   Gourieroux, C., Laurent, J. P., & Scaillet, O. (2000). Sensitivity Analysis of Values at Risk. Journal of Empirical Finance, 7, 225-245.

[2]   Gordy, M., & Lutkebohmert, E. (2007). Granularity Adjustment for Basel II. Discussion Paper Series 2: Banking and Financial Studies, Deutsche Bundesbank.

[3]   Gordy, B., & Lutkebohmert, E. (2013). Granularity Adjustment for Regulatory Capital Assessment. International Journal of Central Banking, 9, 33-71.

[4]   Hannah, L., & Kay, J. A. (1977). Concentration in Modern Industry. London: Mac Millan Press.

[5]   Herfindahl, O. (1950). Concentration in the U.S. Steel Industry. Dissertation, Columbia University.

[6]   Hirschmann, A. (1964). The Paternity of an Index. American Economic Review, 54, 761.

[7]   Lutkebohmert, E. (2009). Concentration Risk in Credit Portfolios. Berlin: Springer.

[8]   Martin, R., & Wilde, T. (2002). Unsystematic Credit Risk. Risk Magazine, 15, 123-128.

[9]   Merton, R. (1974). On the Pricing of Corporate Debt: The Risk Structure of Interest Rates. The Journal of Finance, 29, 449-470.

[10]   Slime, B., & Hammami, M. (2016). Concentration Risk: The Comparison of the Ad-Hoc Approach Indexes. Journal of Financial Risk Management, 5, 43-56.

[11]   Vasicek, O. A. (1987). Probability of Loss on Loan Portfolio. San Francisco: KMV Corporation.

[12]   Wilde, T. (2001). Probing Granularity. Risk Magazine, 14, 103-106.

[13]   Credit Suisse Financial Products (1997). Credit Risk+: A Credit Risk Management Framework. London.