人口減少国 2026

Eastern Europe, past its peak

Forty-nine of the 201 countries in this table have already passed their peak population and are now smaller than they once were. The steepest declines are concentrated in one region: Moldova (down 33.6% from its 1991 peak), Latvia (-31.1% since 1989), Georgia (-30.8% since 1988), Bosnia and Herzegovina (-30.1% since 1991) and Bulgaria (-25.8% since 1988) lead the table, and Ukraine (-24.5% since 1993) is not far behind. Every one of these peaks falls within a few years of the collapse of the Soviet Union and Yugoslavia — the peak years themselves are a visible record of that transition, combining a fertility decline with sustained emigration toward Western Europe that has continued for three decades since.

Decline is not only a poor-country story

Several countries much further along in economic development are on the same list, just earlier in the decline: Japan and Italy, both featured at the top of our median age ranking, have already passed their peak population and are projected to keep shrinking through 2050 and beyond, at more moderate rates than the Eastern European countries above because emigration plays a smaller role for them. Population decline driven mainly by low fertility, once it starts, is difficult to reverse within a generation — the smaller cohort of parents born during the decline will themselves have fewer children even if fertility per woman recovers.

Not everyone has peaked yet

The bottom of this table is exactly where you'd expect: countries whose population hasn't yet passed its high point show 0% here by construction — Papua New Guinea, Vanuatu, Azerbaijan, Kiribati and Syria among them (Syria's population, disrupted by war, is a special case explained in our fastest-growing countries analysis). A 0% today doesn't mean never: under the UN's medium-variant projection, 88 of the 201 countries in this table — just under half — are projected to have a smaller population in 2100 than they do today, most of them on a much longer timetable than Eastern Europe's. See the world population in 2100 ranking for where each country is projected to land.