השוואת שיטות

	Heligman-Pollard Model	Brass Relational Logit Model
תחום	דמוגרפיה	דמוגרפיה
משפחה	Regression model	Regression model
שנת המקור	1980	1971
הוגה השיטה	Larry Heligman & John H. Pollard	William Brass
סוג	Parametric whole-lifespan mortality law	Two-parameter relational mortality model
מקור מכונן	Heligman, L., & Pollard, J. H. (1980). The age pattern of mortality. Journal of the Institute of Actuaries, 107(1), 49–80.	Brass, W. (1971). On the scale of mortality. In W. Brass (Ed.), Biological Aspects of Demography. Taylor & Francis / Barnes & Noble. ISBN: 9780850660425
כינויים	Heligman-Pollard Mortality Law, Eight-Parameter Mortality Model, HP Mortality Model, Heligman-Pollard Ölümlülük Modeli	Brass Logit System, Brass Logit Life-Table Model, Two-Parameter Logit Mortality Model, Brass İlişkisel Logit Modeli
קשורות	4	4
תקציר	The Heligman-Pollard model is an eight-parameter parametric law that describes the age pattern of mortality across the entire human lifespan in a single equation. Introduced by Larry Heligman and John Pollard in 1980, it represents the odds of dying at each age as the sum of three additive components — a rapidly declining childhood term, a young-adult accident hump, and an exponentially rising senescent term — capturing the full characteristic shape of the mortality curve from birth to old age.	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.