Fertility rates (births per woman) have decreased globally from ~3 in 1992 to ~2.3 in 2022, according to information available at Our World in Data. All data was pulled for the most recent available year.

The key figure to note is the replacement rate: 2.1. On a national level, a lower fertility rate than replacement means an aging and decreasing population, an effect that worsens each year the nation can’t reach replacement. This is most critical in states with welfare, which many modern democracies have, as a tipping point can be reached where the young can no longer sustain the old.

Tables

The number of nations with fertility rates below replacement has nearly doubled between 1992 and 2022.

Replacement Status Count of Nations 1992 Count of Nations 2022
At Replacement 170 109
Not at Replacement 67 128

Below is a table including fertility rate alongside economic and development data. Data for some countries is partially or completely unreported.

Gross National Income

A common explanation for the global drop in fertility rate is economic growth and societal development. Nations with greater average wealth, education access and standard of living have historically also had low fertility rates relative to nations lacking in these metrics.

Below is a graph of gross national income adjusted for inflation and cost of living in 2022 compared to fertility rates in the same year for each nation. Gross national income is a per capita (person) average everywhere it appears in this story.

The correlation in this graph is represented by the value displayed beneath it; it is moderately negative, meaning that, in 2022, wealthier nations showed some tendancy toward lower birth rates, and vice versa.

The same was true in 1992:

Though the average fertility rate was much higher, the correlation between wealth and fertility was similar.

So has the change in fertility rate in the last 30 years been spawned from this correlation? Strangely, the answer is no.

By comparing the changes in these data instead of their static values at 1992 and 2022, we confirm that, although wealthy nations tend to have low fertility and poor nations tend to have high fertility, the global change in fertility in the recent decades has been largely independent of this pattern.

Human Development Index

A similar story plays out with Human Development Index, an aggregate statistic designed to reflect the ability of the general population to attain education, high life expectancy and standard of living.

Female Labor Force

Finally, the same holds true for the proportion of women in the labor force of countries as well.

Though the statistics examined here may have once played a substantial role in the decrease of fertility rates across many countries, they do not appear to have their hand in the demographic shift shaping recent history.

Correlations in Numbers

The correlations found in the story were approximated through a calculated value that reflects how strong the correlation is. Generally speaking, a correlation value below 0.5 but above -0.5 is not strong enough to confidently claim the two variables are connected.

The 1992 birth rate versus GNI correlation was -0.5285424. The 2022 birth rate versus GNI correlation was -0.5849392. The change in birth rate versus change in GNI correlation was 0.4833056. The change in birth rate versus HDI correlation was -0.1519343. The change in birth rate versus change in female labor force correlation was 0.0668907.

Story Ideas

As an extension of the efforts made in this story, a true correlation that might explain the global change in birth rate may be explored. Presence or absence of paid parental leave may be one example, though data on that quality proved difficult to extract for this story.

Information and projections on the consequences of demographic collapse will grow increasingly relevant and urgent (as well as the potential that such a change might prove less devastating than expected). Potential exists for stories on this topic.

The topic may benefit from localisation (at a subnational level). Where are people choosing to create families at dispraportionate counts? Where are they not? Why?