手法を比較

	Brass P/F Ratio Method	Total Fertility Rate
分野	人口学	人口学
系統	Process / pipeline	Process / pipeline
提唱年	1964	2001
提唱者	William Brass	Classical demographic index (formalized by Preston, Heuveline & Guillot)
種類	Indirect fertility estimation adjusting period rates using reported parities	Period summary fertility index synthesizing age-specific fertility rates
原典	Brass, W. (1975). Methods for Estimating Fertility and Mortality from Limited and Defective Data. Carolina Population Center, University of North Carolina at Chapel Hill.	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 9781557864512
別名	P/F Ratio Method, Brass P/F Ratio Technique, Parity/Fertility Ratio Method	TFR, Period total fertility rate, Sum of age-specific fertility rates, Toplam Doğurganlık Hızı
関連	4	4
概要	The Brass P/F ratio method is the foundational technique of indirect fertility estimation, designed to correct fertility levels in populations whose vital registration is incomplete but where a census or survey reports both recent births and lifetime children ever born. It compares F — the period fertility a synthetic cohort would have accumulated by each age — with P, the average parity (children ever born) actually reported by women of that age. The ratio of the two diagnoses and corrects errors in the reported level of current fertility, yielding an adjusted total fertility rate from data too defective for direct calculation.	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.