July 22nd, 2014, 10:24 am
The PD% you refer to is the lambda in my asymptotic formula, which specifically would be the risk neutral hazard rate in the flat credit curve scenario. As assumptions go, it may or may not be junky, but it is certainly very crude. To find the value of the risky annuity you take each scheduled payment and multiply by the product of the risk neutral survival probability and the default free discount factor to its date, and add them up (or integrate, if you make the further simplifying approximation of a continuous annuity stream).