
316 Pricing in General Insurance
20.2.3 Exposure Data
In the case of reinsurance, the reinsurer has two options as to what measure of exposure
to use to model a given class of business:
1. Use the original exposure of the reinsured’s clients (such as number of employees
or wageroll for employers’ liability, vehicle years for motor, turnover for public
liability and sum insured for property), after aggregating it at the reinsured’s level
(that is, summing over all the relevant clients of the reinsured).
a. For example, if reinsurer X is reinsuring the motor portfolio of insurer Y, and
insurer Y has clients Z
1
, … Z
k
each with exposure VY