Brass Relational Logit Model

The Brass relational logit model is a two-parameter system for representing and smoothing a life table by relating it to a chosen standard. Introduced by William Brass in 1971, it transforms the survivorship function with a logit and posits that the logits of any two life tables are linearly related, so that an entire age pattern of mortality can be summarized by just two parameters — a level parameter and a parameter governing the balance of childhood versus adult mortality.