Siler Mortality Model

The Siler model is a parametric description of the entire age pattern of mortality, from birth to extreme old age, built as the sum of three competing hazards: a high but rapidly declining risk in early life, a roughly constant background risk through the prime adult years, and an exponentially rising risk of senescence. With just five parameters it reproduces the characteristic U-shaped (or bathtub) mortality curve seen across humans and many animal species. Introduced by William Siler in 1979 for animal mortality, it has become a standard tool in paleodemography, anthropological demography, and comparative life-history studies where a smooth full-lifespan mortality law is needed.