مقایسهٔ روش‌ها

	Relational Gompertz Fertility Model	Total Fertility Rate
حوزه	جمعیت‌شناسی	جمعیت‌شناسی
خانواده	Regression model	Process / pipeline
سال پیدایش	1984	2001
پدیدآور	William Brass; standard refined by Heather Booth	Classical demographic index (formalized by Preston, Heuveline & Guillot)
نوع	Relational parametric model of the cumulative fertility schedule	Period summary fertility index synthesizing age-specific fertility rates
منبع بنیادین	Booth, H. (1984). Transforming Gompertz's function for fertility analysis: The development of a standard for the relational Gompertz function. Population Studies, 38(3), 495–506.	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 9781557864512
نام‌های دیگر	Brass Relational Gompertz Model, Gompertz Relational Fertility Model, Relational Gompertz Function	TFR, Period total fertility rate, Sum of age-specific fertility rates, Toplam Doğurganlık Hızı
مرتبط	4	4
خلاصه	The relational Gompertz model expresses any population's cumulative fertility schedule as a simple linear transformation of a fixed standard schedule, after both are mapped through a double-logarithm (gompit) transform. Developed by William Brass and given its widely used standard by Heather Booth, it characterizes the entire age pattern of fertility with just two parameters — α, which shifts the schedule earlier or later, and β, which controls how concentrated or spread out childbearing is. This makes it a robust tool for smoothing, fitting, and especially for correcting and estimating fertility from the limited and error-prone data common in developing countries.	The total fertility rate (TFR) is the central period measure of fertility in demography: the average number of children a woman would bear over her lifetime if she experienced, at each age, the age-specific fertility rates observed in a given year. Computed by summing age-specific fertility rates across the reproductive ages, the TFR removes the influence of population age structure and gives a single, intuitive figure — children per woman — that is comparable across populations and over time.