The estimation of the profit and loss distribution of a loan portfolio requires the modelling of the portfolio’s multivariate distribution. This describes the joint likelihood of changes in the credit-risk quality of the loans that make up the portfolio. A significant problem for portfolio...

This paper introduces a new model for portfolio credit risk incorporating default and spread widening in a simple and consistent framework. Credit spreads are modelled by geometric Brownian motions with a dependence structure powered by a t-copula. Their joint evolution drives the spreads...