Starting from the Merton framework for firm defaults, we provide the analytics and robustness of the relationship between default correlations. We show that loans with higher default probabilities will not only have higher variances but also higher correlations between loans. As a consequence,...

In credit portfolio modeling the asset correlation parameter is used to describe the degree of default rates fluctuations. In this article we estimate the asset correlation parameter for banks and other industry sectors from default data. We find that estimates of the asset correlation vary...

The 2008-2009 financial crises revealed that the Basel Accord of 2004 was inadequate to ensure a stable financial sector. In this paper we analyze whether the Basel Accord's assumption of a single risk factor contributed to the instability. The asset correlation parameter describes the degree of...

In this paper, we measure the impact of a downturn in the automobile industry on thesolvency of 28 large German banks. The choice of the stressed sector is motivated by theimportant role which the automobile industry plays in the German economy, not the leastbecause of its close ties to other...

This paper sets out to help explain why estimates of asset correlations based on equityprices tend to be considerably higher than estimates based on default rates. Resolving thisempirical puzzle is highly important because, rstly, asset correlations are a key driver ofcredit risk and, secondly,...

Financial institutions are faced with the challenge to forecast future credit portfolio losses.It is common practice to focus on portfolio models consisting of a limited set of parameters,such as the probability of default, asset correlation, loss given default or exposure at default.A simple...

In addition to “classical” approaches, such as the Gaussian CreditMetrics or Basel II model, recentlythe use of other copulas has been proposed in the area of credit risk for modeling loss distributions,particularly T copulas which lead to fatter tails ceteris paribus. As an amendment to...