
432 Pricing in General Insurance
25.2 What’s All This Got to Do with General Insurance?
You will not be surprised to learn that your salary survey is nothing but an allegorical tale
for a situation that actuaries often nd themselves in. Before explaining how the formula
for the credibility estimate works in a general insurance context, let us make the terminol-
ogy clear.
25.2.1 Terminology
The risk premium rate φ for a policy is given by
=
ES
(25.5)
where E(S) is the expected aggregate loss in a given period and w is the expected exposure
in that same period.*
Using the collective risk model assumption, E(S) can be written as E(S) = E(N)E(