The models presented in this section were extensively reviewed in Doray
(2002). One of the first models used in actuarial science for the force of
mortality μx at age x assumed that it was an exponential function of the
attained age. Gompertz (1825) used the two-parameter function
To take into account the force of accidental death, Makeham (1860) added
an extra parameter, assumed to be independent of age, to Gompertz’ model
and obtained