
182 Pricing in General Insurance
be different over the years (if only because of claims ination) or because in some years the
frequency of claims per unit of exposure may be higher/lower because of systemic factors.
Hence, the typical output of the IBNR analysis will look similar to Figure 13.17b.
One of the benets of having a separate projection for each year is that this gives us the
opportunity to estimate the year-on-year volatility of the claim count (after adjusting for
exposure), and t an overdispersed model such as a negative binomial distribution to the
claim count data. In the case shown in Figure 13.17, for example, we can model ...