The most common measure of risk is the variance associated with a particular outcome.
The variance of insurance claims reflects the magnitude of the uncertainty, and how widely these claim values are spread
around the expected (mean) value
.Fu and Khury (2011)note that with in a variance framework, both desirable (e.g., smaller than expected claim payments) and undesirable variations increase risk.
An insurer, however, is only concerned with larger than expected claim payments
as such loss events place a sprain on retained capital and reserves, and
increase the probability of ruin (Fishburn, 1977).
As such,Fishburn (1977)suggested using“lower partial moment”(LPM) instead of the
total variance as the risk measure.
For insurance claims, LPM takes the
following form: