The Age of Migration

In 2020, the rich world crossed a line it had been approaching for half a century: deaths outnumbered births across the World Bank's high-income countries as a group, and they have done so every year since. The gap is not small — about 1.2 million more deaths than births in 2024 — and it is not temporary, because the fertility declines behind it are decades deep. Yet the rich world's population keeps growing. It added roughly two million people in 2024, and in net terms every one of them arrived from somewhere else.

That is the quiet architecture of this century's demography. Migration stopped being a detail of rich-world population arithmetic around the turn of the millennium — it has exceeded natural increase across high-income countries every year since 1999 — and it has now become the whole of it.

The United States is the constant. Nine of the ten largest single-year intakes in the whole sixty-five-year record are American — between 1.6 and 1.9 million a year through the 2010s. (The tenth is Ukraine in 2025: refugees coming home.) What has changed is what the intake is for. In 1990 the United States generated two million more births than deaths a year; by 2024 that surplus had shrunk to 544,000, while net migration ran at 1.3 million. Migration has out-added natural increase in America every year since 2010 — the first year of the record in which that was true — and now supplies about seventy percent of its growth.

Germany is the pure experiment. It has not recorded a single year of natural increase since 1972. Fifty-two years of deaths outrunning births should have shrunk it by about seven million people; instead, net migration added thirteen million over the same period — Turkish and Yugoslav guest workers, more than 800,000 post-Soviet arrivals in 1992 alone, 1.2 million in the Syrian summer of 2015, close to a million in the Ukrainian spring of 2022 — and Germany's population touched its all-time peak, 83.5 million, in 2024. A country that has not replaced itself in half a century, at its largest ever.

Germany has not had a year of more births than deaths since 1972. Its population peaked in 2024.

The arithmetic flips

Country by country, the same crossing repeats. Spain has buried more people than it has borne every year since 2017; its population reached a record 49.4 million in 2025 anyway. Italy's births fell below its deaths in 1994 and — a single-year blip in 2004 aside — never came back. Britain's natural surplus has all but vanished, down to 13,000 in 2024 next to net migration of 417,000. Canada's 2023 growth was 95 percent migration.

Japan is the control group: the country that shows what the arithmetic does on its own. Deaths have exceeded births there every year since 2007, migration stayed small, and the population has fallen from its 2010 peak of 128 million to about 124 million. Even that is softening — Japan has run net migration around 150,000 a year since 2022, quietly high by its own history — but the chart still slopes down. Without large-scale arrival, that is the shape.

The sending side

Every arrival is a departure, and the sending half of the ledger keeps its own history. The most violent line in the record is Ukraine's: net migration of minus 5.7 million in 2022, the largest single-year outflow of the past sixty-five years, followed by the beginnings of a return — plus 1.1 million in 2024, plus 1.7 million in 2025. Syria's worst year, 2013, subtracted two million people.

War moves people in millions per year; economics moves them in millions per decade. Venezuela's collapse subtracted 4.8 million people between 2014 and 2024. India, the world's largest sender, has netted out about 12 million departures since 2000 — a number that barely dents 1.4 billion. And Mexico, whose exodus defined American immigration politics for a generation, sent north a net six million people between 1990 and 2010; the wave has since faded to about 100,000 a year.

None of this changes the planet's total — at the world scale migration nets out to zero, and the global slowdown remains a story of births and deaths. What it changes is the map. Since 1990, high-income countries have absorbed a net 149 million people, a transfer with no precedent in the peacetime record, and it is now the only mechanism by which most of the rich world grows at all. Which is why the deepest demographic questions of the century — who staffs the hospitals, who fills the schools, whose pension arithmetic survives — are increasingly settled not in maternity wards but at borders.

The word migration enters most public arguments as a disruption. The ledger records it differently: as the load-bearing column under rich-world population growth, quietly assuming weight for thirty years while natural increase drained away. The politics of every high-income democracy now runs, one way or another, on the tension between those two readings. The chart does not resolve it. It only shows, with some precision, what the column is holding up.

Every figure identifies its source. See SPHRE sources and methodology.