为什么Marginal PD不会一直增加呢？

NO.PZ2016082405000066

Which of the following statements about cumulative and marginal default probabilities is most accurate?

选项：

Both functions increase over time.

Neither function increases over time.

Only the cumulative default probabilities increase over time.

Only the marginal probabilities increase over time.

解释：

C The cumulative default probability function begins at zero and eventually reaches 100% and must therefore increases over time. Marginal probabilities of default are always positive but are not necessarily increasing over time.

为什么Marginal PD不会一直增加呢？之前老师讲过如果一家信用质量比较好的公司他的Marginal PD会越来越大