The parameters of death: a consideration of the quantity of information in a life table using a polynomial representation of the survivorship curve.
How much unique information is contained in any life table? The logarithmic survivorship (lx) columns of 360 empirical life tables were fitted by a weighted fifth degree polynomial, and it is shown that six parameters are adequate to reproduce these curves almost flawlessly. However, these parameters are highly intercorrelated, so that a two-dimensional representation would be adequate to express the similarities and differences among life tables. It is thus concluded that a life table contains but two unique pieces of information, these being the level of mortality in the population which it represents, and the relative shape of the underlying mortality curve.
Anson
J
J
Department of Social Work, Ben Gurion University of the Negev, Beer Sheba, Israel.
D000206:Actuarial Analysis / Q000379:methods*; D005260:Female; D006801:Humans; D008017:Life Expectancy; D008297:Male; D009026:Mortality