Сравнение на методи

	Parity Progression Ratio	Total Fertility Rate
Област	Демография	Демография
Семейство	Process / pipeline	Process / pipeline
Година на възникване	1953	2001
Създател	Louis Henry (formalized in modern demography)	Classical demographic index (formalized by Preston, Heuveline & Guillot)
Тип	Order-specific fertility measure built from a sequence of conditional progression probabilities	Period summary fertility index synthesizing age-specific fertility rates
Основополагащ източник	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 9781557864512	Preston, S. H., Heuveline, P., & Guillot, M. (2001). Demography: Measuring and Modeling Population Processes. Blackwell. ISBN: 9781557864512
Други названия	PPR, Birth progression ratio, Parity progression probability, Doğum Sırası İlerleme Oranı	TFR, Period total fertility rate, Sum of age-specific fertility rates, Toplam Doğurganlık Hızı
Свързани	4	4
Резюме	A parity progression ratio is the conditional probability that a woman who has already had a given number of children goes on to have one more. By converting a static parity distribution into a sequence of birth-by-birth transition probabilities, the method reveals where childbearing stops within a cohort and lets demographers rebuild completed fertility from the bottom up. It is the natural fertility analogue of a survival or life-table transition, treating each additional birth as a further step a woman may or may not take.	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.