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Frequency Modelling: Adjusting
for Claim Count IBNR
We now get into the heart of the frequency/severity model. We rst turn our attention to
frequency modelling. Because producing a frequency model means calculating the char-
acteristics of the frequency distribution such as its mean and its variance, we need to know
the ultimate claim count for each year. However, the only information we have is the num-
ber of claims reported in any particular year. To go from the reported claim count to the
ultimate claim count, we need to estimate the number of incurred but not (yet) reported
(IBNR) claims. The objective of this section is to illustrate ...