Why is fertility falling?

Pick a country and switch indicators on: they all line up on one time axis. You can see what changed together, what came first, where official forecasts point and how far past ones missed. Under the chart: observations computed from what is on screen.

Fertility (TFR)children per woman2.25 2023

Urban share% of population57.8% 2025

Women in tertiary education% gross46.5% 2024

Internet% of population73.6% 2025

GDP per person (PPP)constant 2021 international $21,914 PPP dollars 2025

actualcurrent UN forecastUN low variantUN 95% interval

Without JavaScript you see a ready view: World — Total fertility rate, Urban population, Tertiary enrolment, women, Internet users, GDP per capita, PPP, 1950–2050. Every country has its own page that works without JavaScript (list below); the data is in the API.

How the indicators changed

Fertility (TFR): 4.85 in 1950 → 2.25 in 2023 (−54%). Peak: 5.31 in 1963; the latest value is 58% lower. The trend broke around 1965 and 1993: +0.01 → −0.07 → −0.02 a year.
Urban share: 34.2% in 1960 → 57.8% in 2025 (+24 pp). Threshold: above 50% since 2007. The trend broke around 2018: change slowed down (+0.51 → +0.28 a year).
Women in tertiary education: 12.9% in 1970 → 46.5% in 2024 (+34 pp). Low: 7.4% in 1971; +39 pp since then. The trend broke around 1991: change sped up (+0.2 → +0.73 a year).
Internet: 15.6% in 2005 → 73.6% in 2025 (+58 pp). Threshold: above 50% since 2019. Fastest growth in 2017–2022: 46.3% → 67%.
GDP per person (PPP): 11,275 PPP dollars in 1990 → 21,914 PPP dollars in 2025 (+94%). The trend broke around 1998: change sped up (+109 → +356 a year).

What changed at the same time

The fastest decline of "Fertility (TFR)" was in 1968–1978: 4.96 → 3.79. Over the same years: urban share 36% → 38.6%; women in tertiary education 10% (1978); no data for the others in those years.
Over the last 10 years (2013–2023): fertility (TFR) 2.57 → 2.25; urban share 53.4% → 57.3%; women in tertiary education 34.8% → 46.2%; internet 35.3% → 69.2%; GDP per person (PPP) 17,122 PPP dollars → 20,895 PPP dollars.

How the indicators relate

Fertility (TFR) and urban share (1960–2023, 64 years): levels are strongly related, in opposite directions (r = −0.92); year-to-year changes are weakly related (r = −0.29).
Fertility (TFR) and women in tertiary education (1970–2023, 54 years): levels are strongly related, in opposite directions (r = −0.82); year-to-year changes show no reliable link (r = 0.16). This looks like a shared trend: both change over time, but not in step from year to year. Changes line up best when shifted by 8 years: "Fertility (TFR)" moves first, then "Women in tertiary education" (r = −0.63).
Fertility (TFR) and internet (2005–2023, 19 years): levels are strongly related, in opposite directions (r = −0.96); year-to-year changes are weakly related (r = −0.47).
Fertility (TFR) and GDP per person (PPP) (1990–2023, 34 years): levels are strongly related, in opposite directions (r = −0.91); year-to-year changes are weakly related (r = 0.36).

Forecasts vs actual

Fertility (TFR): past UN projections. The outcome was below the projection in 3 of 11 revisions (1998–2022) and above in 8; median gap +2.1%.
The UN 1998 projection expected this level (2.25) already around 2020: reality is 3 years behind it.
The UN 2008 projection expected today's level (2.25, 2023) only by 2025–2030: reality is at least 2 years ahead of it.
Fertility (TFR): UN 2024 projection (medium): 2050 — 2.10 (−7% vs 2023), 2100 — 1.84 (−18% vs 2023); low variant for 2100: 1.36.

Moving together in time does not prove a cause: incomes, cities, education and the era itself act on many indicators at once. These observations suggest where to look, not what causes what.

World · API

Key findings

UN projection of 2024: in 33 of 42 countries that already report 2024–2025 data, births are below the medium variant; in 8, below the lower bound of the 95% interval.
Japan: 709k births in 2024 (including children of foreign nationals). Even the latest official projection (IPSS 2023, medium) expected this level only in 2042, 18 years later. An earlier projection (IPSS 2002, medium) expected it in 2045.
Taiwan: 108k births in 2025. Even the latest official projection (NDC 2024, medium) expected this level only in 2036, 11 years later. An earlier projection (NDC 2016, medium) expected it in 2057.
China: 7.92M births in 2025. Even the latest official projection (UN WPP 2024, medium) expected this level only in 2050, 25 years later. An earlier projection (UN WPP 2022, medium) expected it in 2054.
United States: 1.60 children per woman in 2024. The SSA 2015 projection assumed 2.04 for that year, a gap of −22%.
South Korea: 0.80 children per woman in 2025. Projections made before 2020 expected 1.00–1.38 for 2025, while the 2021 and 2023 projections turned out lower than reality: fertility rose slightly in 2024–2025. Errors go both ways.
World: 67% of people live in countries with fertility below replacement (2.1), 31% below 1.5. World population is still growing: the UN expects a peak of about 10.3B in 2084.

All forecast-vs-actual checks →

How it works

A source for every number. Links go to the primary publication: the statistical office, the UN, the projection archive.
Forecast against fact. Next to a figure: what official projections expected for it and how far reality departed.
Association is not cause. Moving together in time suggests where to look; the observations under the chart always say so and check a link not only in levels but also in year-to-year changes.
Open data. Every table is available as CSV and JSON to check, recompute and reuse.
For programs and AI agents. The same data through an API and an MCP server, no page scraping: how to connect.

Data as of 7 October 2026

Country pages

Each country has a page that works without JavaScript: key indicators, observations, past UN and IMF forecasts against actual data, every series with source links. Countries →