This paper introduces a test for zero correlation in situations where the correlation matrix is large compared to the sample size. The test statistic is the sum of the squared correlation coefficients in the sample. We derive its limiting null distribution as the number of variables as well as...

Under the advanced internal ratings-based (AIRB) approach, the banks are allowed to use their internally developed models for probability of default (PD), exposure at default (EAD) and loss given default (LGD) parameters. According to the Basel II Accord (2004), the potential over-optimism of...

In small samples and especially in the case of small true default probabilities, standard approaches to credit default probability estimation have certain drawbacks. Most importantly, standard estimators tend to underestimate the true default probability which is of course an undesirable...

This paper deals with stress tests for credit risk and shows how exploiting the discretion when setting up and implementing a model can drive the results of a quantitative stress test for default probabilities. For this purpose, we employ several variations of a CreditPortfolioView-style model...

This paper studies the relationship between the riskiness of banks' assets and their average risk weight. Banks' initial risk weights explain about half of the variation in projected credit losses in the 2018 European Banking Authority stress test. In contrast to related papers, this paper also...