قارن الطرق

	Mean Age at Childbearing	Net Reproduction Rate
المجال	علم السكان	علم السكان
العائلة	Process / pipeline	Process / pipeline
سنة النشأة	1968	2001
صاحب الطريقة	Standard demographic practice (fertility schedule moments)	Richard Böckh and Robert Kuczynski (formalized in Preston, Heuveline & Guillot)
النوع	Summary location measure of the age pattern of fertility	Period measure of generational replacement combining fertility and mortality
المصدر التأسيسي	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
الأسماء البديلة	MAC, Mean age of the fertility schedule, Mean age of mothers at birth, Ortalama Doğurganlık Yaşı	NRR, Net reproduction ratio, Net reproductive rate, Net Üreme Hızı
ذات صلة	4	4
الملخص	The mean age at childbearing is the average age of mothers at the birth of their children, computed as the fertility-rate-weighted mean of maternal age over the age-specific fertility schedule. As the first moment of the fertility curve, it summarizes the tempo — the timing — of childbearing in a single number, complementing the total fertility rate, which measures quantum, or how many children are born.	The net reproduction rate (NRR) is the demographic measure of generational replacement: the average number of daughters a woman would bear who survive to the age their mother was when she bore them, given the period's age-specific fertility rates and female mortality. By combining fertility with survival, the NRR answers the fundamental question of whether a population is replacing itself — an NRR of one means each generation of women exactly reproduces the next, below one signals long-run decline, and above one signals growth.