In the past people had many more children than today. The number fluctuated over time and there were some differences between countries, but for much of our history, the average woman had at least five children, and often more. Two centuries ago this was true for the US, the UK, Russia, India, China and many other countries for which we have data.
The metric demographers use to measure offspring per parent is the Total Fertility Rate. The TFR is defined as the average number of children that would be born to a woman over her lifetime if the woman were to experience the current age-specific fertility rates throughout her lifetime.1 It is a metric that captures the fertility rate in one particular year rather than over the life course of a generation of women – it is a period, not a cohort metric. [More information on the measurement you find the relevant section below].
From 1950 onwards we have very good data from the UN Population Division. The chart below shows the average: the global Total Fertility Rate. Up to 1965 the average woman in the world had more than 5 children. Since then we have seen an unprecedented change. The number has halved. Globally, the average per woman is now below 2.5 children.
Why has the global fertility rate fallen so rapidly?
We discuss the reasons for this change in this detailed section below. The three major reasons are the empowerment of women (increasing access to education and increasing labour market participation), declining child mortality, and a rising cost of bringing up children (to which the decline of child labor contributed).
As a consequence of the declining global fertility rate the global population growth rate has declined, from a peak of 2.1% per year in 1968 to less than 1.1% today. In our discussion on the global population rate, we explain that we are therefore in the transition to a new balance where rapid population change will come to an end. “The big global demographic transition that the world entered more than two centuries ago is then coming to an end: This new equilibrium is different from the one in the past when it was the very high mortality that kept population growth in check. In the new balance it will be low fertility keeps population changes small.”
How the fertility rate changed country-by-country is shown in the following section. But you can also add any country or world region to the chart right here by clicking on ‘ Add country ’.
