Makeham

Makeham is an English surname and, in actuarial science and demography, it is associated with Makeham's law, a mortality model named after William Makeham. He introduced a constant term to the Gompertz law of mortality, improving its fit to observed data.

Makeham's law expresses the instantaneous mortality rate at age x as μ(x) = A + B c^x, where A, B, and c are positive constants with c > 1. The term A, known as the Makeham term, represents age-independent mortality from external or non-age-related hazards. The component B c^x captures the increasing mortality risk that grows with age. Together, the two components provide a more flexible description of mortality across ages than the Gompertz model alone.

In practice, Makeham's law is used in actuarial science, demography, and related fields to construct life tables and to model risk in life insurance, pensions, and population studies. Variants and extensions—such as the Gompertz-Makeham form—are employed to accommodate different populations and data sets.

The Makeham surname has its origins in England and appears in historical records and biographies related to mathematics and actuarial science. Beyond the term Makeham’s constant, the name is encountered in academic references tied to the development and application of mortality models.