A measure of the life expectancy of current and future pensioners and other beneficiaries of a pension scheme.
From the perspective of the pensions provider, there is therefore a related 'longevity risk'.
Longevity risk refers to the increased cost of providing pensions, resulting from improvements in health and increases in average life expectancy.
A closely related term in pensions valuation and management is 'mortality'.
Mortality refers to the relative proportions of groups of pension scheme members who are expected to die in a given period.
So as mortality rates decrease, average life expectancy increases accordingly.