Macroscope
RU

Ageing

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.

Median ageyears30.4 years 2023
20253035
Old-age dependencypersons 65+ per 100 aged 20-6416.4 per 100 aged 20–64 2020
0102030
Life expectancyyears73.5 years 2024
506070
Mean age at childbirthyears28.2 years 2023
272829
actualcurrent UN forecastUN low variantUN 95% interval

Without JavaScript you see a ready view: World — Median age, Old-age dependency, Life expectancy at birth, Mean age of mothers at childbirth, 1950–2050. Every country has its own page that works without JavaScript (list below); the data is in the API.

How the indicators changed

  • Median age: 22.2 years in 1950 → 30.4 years in 2023 (+8.2 years). Low: 20.3 years in 1969; +10 years since then. Threshold: above 30 years since 2022. The trend broke around 1971: direction reversed (−0.1 → +0.14 a year).
  • Old-age dependency: 10 per 100 aged 20–64 in 1950 → 16.4 per 100 aged 20–64 in 2020 (+6.4 per 100 aged 20–64).
  • Life expectancy: 50.9 years in 1960 → 73.5 years in 2024 (+23 years). Thresholds: above 60 years since 1975, above 70 years since 2008. The trend broke around 1966: change slowed down (+0.72 → +0.38 a year).
  • Mean age at childbirth: 28.9 years in 1950 → 28.2 years in 2023 (−0.7 years). The trend broke around 1968 and 1994: −0.01 → −0.07 → +0.05 a year.

What changed at the same time

  • The fastest rise of "Median age" was in 2013–2023: 27.8 years → 30.4 years. Over the same years: life expectancy 71.5 years → 73.3 years; mean age at childbirth 27.7 years → 28.2 years; no data for the others in those years.

How the indicators relate

  • Median age and old-age dependency (1950–2020, 15 years): levels are strongly related, in the same direction (r = 0.90); year-to-year changes show no reliable link (r = —). This looks like a shared trend: both change over time, but not in step from year to year.
  • Median age and life expectancy (1960–2023, 64 years): levels are strongly related, in the same direction (r = 0.91); year-to-year changes show no reliable link (r = 0.10). This looks like a shared trend: both change over time, but not in step from year to year.
  • Median age and mean age at childbirth (1950–2023, 74 years): levels are barely related (r = −0.36); year-to-year changes are weakly related (r = −0.39).

Forecasts vs actual

  • Mean age at childbirth: past UN projections. The outcome was above the projection in 9 of 12 revisions (1998–2022) and below in 3; median difference +0.5 years. The biggest miss: the 1998 revision expected 26.6 years for 2020–2025; the outcome was 28.2 years (for the years of the period so far).
  • Mean age at childbirth: UN 2024 projection (medium): 2030 — 28.5 years, 2050 — 29 years, 2100 — 30.2 years.

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.

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 →