
98 Pricing in General Insurance
When one looks more closely at the details of the application of the collective risk model
to motor eet losses, some additional difculties emerge.
First, each vehicle can have more than one loss, but if it crashes too badly, it will have
to be written off and will therefore not be able to have further losses – in other words, the
underlying eet has changed and so the overall risk changes and the initial model will
not, strictly, be valid anymore (although it will probably be replaced). Actually, we can
generalise this a bit further, by considering that vehicles may be removed from or added
to the eet for a number ...