Fertility rate
From Free net encyclopedia
Image:Fertility rate world map.PNG The (total) fertility rate (or total period fertility rate) of a population is the average number of children that would be born to a woman over her lifetime if she were to experience the current age-specific fertility rates through her lifetime. It is obtained by summing the age-specific rates for a given time-point.
It is a better index of fertility than the birth rate (annual number of births per thousand women of childbearing age) because it is independent of the age structure of the population, but it is a poorer estimate of actual completed family size than the total cohort fertility rate, which is obtained by summing the age-specific fertility rates that actually applied to each cohort as they aged through time. In particular, the TPFR does not predict how many children young women now will eventually have, as their fertility rates in years to come may well differ from those of older women now. However, the TPFR is a good summary of current fertility.
Replacement rates
Replacement fertility is the total fertility rate at which women would have only enough children to replace themselves and their partner. By definition, replacement is only considered to have occurred when the offspring reach 15 years of age. If all offspring survived to the age of 15 the replacement rate would be exactly 2, but in practice it is affected by childhood mortality. The replacement fertility rate is roughly 2.1 births per woman for most industrialized countries and has not been evaluated for poorer countries. At this rate, populations growth through reproduction will be approximately zero, but will also be affected by male-female ratios.
Developed countries usually have a much lower fertility rate due to greater wealth and their individualistic culture. Mortality rates are low, birth control is easily accessible, and children often can become an economic drain caused by education costs, clothing and feeding. Longer periods of time spent getting higher education often mean young people are marrying later in life giving them less time to have kids. In developing countries on the other hand, children are a necessity as labour in fields and as caregivers and providers of their parents in old age. Fertility rates are also higher due to the lack of access to contraceptives.
See also
External links
- World Factbook table of Total Fertility Rate ordered by country name
- World Factbook table of Total Fertility Rate ordered by country rank
Template:Statistics-stubcs:Plodnost de:Fertilitätsrate es:Tasa de fertilidad hu:Termékenységi ráta pt:Taxa de fecundidade ru:Коэффициент фертильности