The TFR is not based on the fertility of any real group of women since this would involve waiting until they had completed childbearing. Nor is it based on counting up the total number of children actually born over their lifetime.

The term "lowest-low fertility" is defined as TFR at or below 1.3. This is characteristic of some Eastern European, Southern European, and East Asian countries. For example, in 2001, more than half of the population of Europe lived in countries with the lowest-low TFR,

Fertility factors are determinants of the number of children that an individual is likely to have. Fertility factors are mostly positive or negative correlations without certain causations

From around 10,000 BC to the beginning of the Industrial Revolution fertility rates around the world were high by today’s standards, but the onset of the Industrial Revolution, around 1800, brought about what has come to be called the Demographic Transition,

Net reproduction rate
An alternative fertility measure is the net reproduction rate (NRR), which measures the number of daughters a woman would have in her lifetime if she

A population that maintained a TFR of 3.8 over an extended period without a correspondingly high death or emigration rate would increase rapidly (doubling period ~ 32 years),

Governments have often set population targets, to either increase or decrease the total fertility rate; or to have certain ethnic or socioeconomic groups have a lower or higher fertility rate. Often such policies have been interventionist, and abusive. The most notorious