The pricing of portfolio credit risk

BIS Working Papers No 214
September 2006

Abstract:

Equity and credit-default-swap (CDS) markets are in disagreement as to the extent to which asset returns co-move across firms. This suggests market segmentation and casts ambiguity about the asset-return correlations underpinning observed prices of portfolio credit risk. The ambiguity could be eliminated by - currently unavailable - data that reveal the market valuation of low-probability/large-impact events. At present, judicious assumptions about this valuation can be used to reconcile observed prices with asset-return correlations implied by either equity or CDS markets. These conclusions are based on an analysis of tranche spreads of a popular CDS index, which incorporate a rather small premium for correlation risk.

JEL classification: G13, C15.

Keywords: CDS index tranche, joint distribution of asset returns, correlation risk premium, copula