arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1706.09809q-fin.RM
收藏

信用风险中的极端投资组合损失相关性

Extreme portfolio loss correlations in credit risk

Andreas Mühlbacher, Thomas Guhr

摘要:

金融体系的稳定与系统性风险因素有关,例如许多小债务人同时违约。因此,在大量重叠的信贷组合的情况下,研究不同债权人损失的相互依赖性至关重要。在非平稳市场上,我们分析计算了多个信用组合的多元联合损失分布。考虑到波动的资产相关性,我们使用一个随机矩阵的方法,保留,作为一个非常赞赏的副作用,分析的易处理性,并大大减少了参数的数量。我们发现,两个不相交的信贷组合的多样化不工作在一个相关的市场。此外,我们发现大量的同时投资组合损失是相当可能的。我们发现,显着的相关性的损失出现不仅为大型投资组合,数以千计的信用合同,但也为小的投资组合组成的几个信用合同。此外,我们还包括次级级别,这是在债务抵押债券中建立的,以保护更高级的部分免受高额损失。我们通过分析证实了这样的观察,即次级债权人的极端损失也可能导致高级债权人的巨大损失。

英文摘要:

The stability of the financial system is associated with systemic risk factors such as the concurrent default of numerous small obligors. Hence it is of utmost importance to study the mutual dependence of losses for different creditors in the case of large, overlapping credit portfolios. We analytically calculate the multivariate joint loss distribution of several credit portfolios on a non-stationary market. To take fluctuating asset correlations into account we use an random matrix approach which preserves, as a much appreciated side effect, analytical tractability and drastically reduces the number of parameters. We show that for two disjoint credit portfolios diversification does not work in a correlated market. Additionally we find large concurrent portfolio losses to be rather likely. We show that significant correlations of the losses emerge not only for large portfolios with thousands of credit contracts but also for small portfolios consisting of a few credit contracts only. Furthermore we include subordination levels, which were established in collateralized debt obligations to protect the more senior tranches from high losses. We analytically corroborate the observation that an extreme loss of the subordinated creditor is likely to also yield a large loss of the senior creditor.

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。

↑