Hogg & Klugman

Dugan, Stephen ( (no email) )
Wed, 15 Jul 1998 08:28:01 -0500

I have a question about Hogg & Klugman from the 1996 exam, question
37.....

When there is no deductible, the expected frequency is 0.1 and the
expected severity is $200.

With a franchise deductible of $100, the expected frequency becomes
0.025 and the expected severity becomes $600.

If X is a random variable representing a claim (prior to imposing the
deductible), then what is the limited expected value E[X;100]?

Solution:

E[X;d] = E[X] - (E[W] - d)(1 - Fx(100))

Where (1 - Fx(100)) = (Frequency with Franchise Deductible)/p =
0.025/0.1 = 0.25

E[X;d] = 200 - (600 - 100)(0.25) = 75

My Question:

It is not obvious to me that (1 - Fx(100)) is simply the ratio of the
two frequencies. Since the solution hinges on knowing this "fact", can
anyone explain in words why this is? Thanks.

SD.