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arXiv 1012.0249q-fin.RMq-fin.ST
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操作风险的稳健估计

Robust Estimation of Operational Risk

Nataliya Horbenko, Peter Ruckdeschel, Taehan Bae

摘要:

根据损失分布法,银行的操作风险被确定为相应损失分布的99.9%分位数,包括意外严重事件。99.9%分位数可以被认为是尾部事件。根据Pickands-Eschema-de Haan定理,超过某个高阈值的尾事件通常由广义帕累托分布(GPD)建模。GPD尾部分位数的估计不是一项简单的任务,特别是如果考虑到这种分布的重尾,奇异离群值的可能性,以及数据通常在几个来源之间合并的事实。此外,如果像通常情况那样,运营损失是匿名汇集的,则相应银行的拟合数据的相关性不是不言而喻的。在这种情况下,当经典方法已经失败时,鲁棒方法可以提供稳定的估计。本文将最优稳健性方法MBRE、OMSE、RMXE引入操作风险的应用领域。我们应用这些程序的参数估计的GPD在数据来自美国加州大学洛杉矶分校。为了更好地理解这些结果,我们提供了针对此背景进行调整的支持性诊断图:影响图,离群图和具有稳健置信带的QQ图。

英文摘要:

According to the Loss Distribution Approach, the operational risk of a bank is determined as 99.9% quantile of the respective loss distribution, covering unexpected severe events. The 99.9% quantile can be considered a tail event. As supported by the Pickands-Balkema-de Haan Theorem, tail events exceeding some high threshold are usually modeled by a Generalized Pareto Distribution (GPD). Estimation of GPD tail quantiles is not a trivial task, in particular if one takes into account the heavy tails of this distribution, the possibility of singular outliers, and, moreover, the fact that data is usually pooled among several sources. Moreover, if, as is frequently the case, operational losses are pooled anonymously, relevance of the fitting data for the respective bank is not self-evident. In such situations, robust methods may provide stable estimates when classical methods already fail. In this paper, optimally-robust procedures MBRE, OMSE, RMXE are introduced to the application domain of operational risk. We apply these procedures to parameter estimation of a GPD at data from Algorithmics Inc. To better understand these results, we provide supportive diagnostic plots adjusted for this context: influence plots, outlyingness plots, and QQ plots with robust confidence bands.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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