August 28th, 2008, 6:07 am
QuoteOriginally posted by: CreditJediOne thing I've never understood is the relationship between the probability of default/survival and the recovery rate. I've never much liked the JPM paper because it over complicates something rather simple that can be explained intuitively. Yet there P(D) as well as a MER paper I read are a function of a hazard rate. Yet in the same paper they go on to show graphs of the different survial curves (time on x axis, probability on y axis) for different recovery rates (curves of various convexity). Now, I've never seen a paper which relates the two in a mathematical and intuitive way. For me the cumulative P(S) = exp(-ht) where h is the hazard rate and t time. It is not a function of R so how do they plot those graphs? Am I missing something, but to me and the alegbra I know from the original paper, R is simply acts as a scalar to compute the expected loss. This will affect the ultimate spread but not the underlying probabilities. Can someone please help?...well..your market data is the quoted spread, so from that data and the recovery (typical assumption: fixed recovery) you have to obtain the hazard rate. Imagine a single period CDS: if Dflt Occurs you pay 1-R at Mty, otherwise you received the spread pymnt at Mty. neglecting dyacount fraction and discount factors and assuming your reference is alive today you will Get something like the following expresion to calculate the breakeven spread: NPV = 0 = S*P-(1-R)*(1-P) P beeing survival probability up to Mty. this way you get P = 1/(1+S/(1-R)) so P = f(S,R) and so is your hazard rate. Note that S is your market data...you know it so you are left with a function of the assumed recoverydoe this solve your doubt?