freehp 发表于 2009-11-13 18:14 
第44题 答案为B
根据KMV模型 投资组合的未预期信用损失公式求的。
consider the following assumptions for Borrower B: Expected Loss on loan is 5.5%, Expected defaulty frequency is 5%, Annual all-in-spread is 5.8%, Based on the KMV portifolio manger model, what is the unexpected loss on the loans for borrower B? A.4.72% B.10.5% C.2.64% D.12.42%
原题还有个条件EDF(B)=48%。
所以UL=LGD*(EDF*(1-EDF))^0.5=48%*(5%*(1-5%))^0.5=10.46%
答案为B
EDF(B)=48%,应该是LGD=48%,对吗?而UL=LGD*(EDF*(1-EDF))^0.5这个公式能文字说明一下吗?EDF*(1-EDF) 是 variance of a process assume a possion process with n=1? 可是使用possion的前提是np足够大啊,n=1, p=5%,不满足条件啊,这个公式出自哪里呢?谢谢指教!