On the human survivorship function and life table construction

The construction of life tables is often marred by one or more of the following restrictions: (1) assumptions that are either unjustifiable or of questionable generality; (2) rough approximations; (3) exacting data requirements. This paper recommends instead a simple method which regards the force of mortality as constant within each age interval. The reasoning is readily comprehensible and all life table functions are easily calculated from the age-specific death rates without any need for further assumptions, approximations, or data. Furthermore, this method produces numerical results that are close to those obtained by other methods.