B3 EQUITABLE PREMIUMS
It is clear that there can be several of these pools; one for each main type of risk.
The people who have a house to insure would not contribute to the same pool as insuring a car.
Operating in this way allows an insurer to identify which types of insurance are profitable and which are not.
In reality there may be some transferring of funds across the pools, but at this stage it is simpler for us to imagine individual pools for different types of risk.
Even when risks of a similar type are brought together in a common pool, they do not all represent the same degree of risk to the pool itself.
That is, the probability of a loss having to be met by the pool is not equal over all those in the pool.
For example, a timber built house represents a different risk from one of standard brick construction; an 18 year old driver, with a fast sports car, is quite a different risk from a 40 year old married man, driving a family saloon; an employee using woodworking machinery is probably at greater risk of personal injury than someone who spends their working days in an office.