Cambodia’s Closing Window: A Demographic Dividend on a Deadline

Thailand’s demographic story gets the headlines: a country growing old before it grew rich, with deaths now outpacing births and a fertility rate among the lowest on Earth. The more useful place to look, though, is next door. In Cambodia the same process is running roughly a generation behind — and unlike Thailand’s, the outcome is still open.

It is tempting to frame Cambodia as the regional outlier, the high-birth-rate country in an ageing neighbourhood. The data tell a more interesting story. Cambodia’s fertility is not high so much as late, and it is falling fast. The question that matters for the next two decades is not why Cambodians are still having children, but whether the country can convert its remaining years of youth into wealth before the window shuts — exactly the test Thailand is now failing.

Contents

• Not high, just late
• Why the rate sits where it does
• The echo, not the engine
• The dividend, and the deadline
• Thailand is the warning
• The same road, with a smaller head start

Not high, just late

Cambodia’s total fertility rate sits at roughly 2.5 children per woman, only marginally above the replacement level of 2.1.¹ By United Nations estimates the figure stood at about 2.51 in 2025, and it has now declined every year for six years running.³ The country’s own planners expect it to keep falling: a 2025 policy brief from Cambodia’s Ministry of Planning, produced with UNFPA, projects the rate dropping to 2.04 — below replacement — by 2050.²

This is the shape of a country moving through the standard demographic transition, not one stuck at the top of it. Cambodian fertility neared six children per woman as recently as the early 1980s; it has more than halved since.⁶ The reason it looks high is the company it keeps. Set beside Thailand — where the rate is somewhere between 0.9 and 1.4 depending on which dataset you trust — almost anything looks fertile. The honest framing is not that Cambodia is an exception, but that it is a lag: the same curve, a generation behind.

Why the rate sits where it does

So why is Cambodia’s rate higher than its neighbours’ at all? The most straightforward answer is development, and geography. Cambodia remains a predominantly rural society — only around a quarter of the population lives in urban areas — and rural fertility everywhere tends to run ahead of urban fertility, tracking later marriage, later schooling and slower shifts in the economics of raising children.⁸

Family planning fills in the rest. Modern contraceptive use among married women in Cambodia was about 45% in the 2021–22 Demographic and Health Survey — well short of the figures recorded in the Philippines (around 57%) or Myanmar (around 56%).⁴ Unmet need remains stubborn: roughly one in eight married Cambodian women who would prefer to delay or stop childbearing are not using any method, one of the higher rates of unmet need in the region.⁵ None of this points to a population that wants large families. It points to a transition that is still in progress, held up by access and income rather than preference. As those gaps close — and the contraceptive and education trends say they are closing — the rate has only one direction to travel.

The echo, not the engine

The intuitive explanation — that Cambodia’s birth rate is still elevated by a rebound after the Khmer Rouge — is half right and several decades out of date. Fertility did collapse under the regime, which killed roughly a quarter of the population between 1975 and 1979; demographers estimate the rate fell to around 3.7 births per woman during those years, sharply below its pre-war level.⁶ And the recovery was dramatic. After the regime fell, marriages and births surged, pushing the crude birth rate as high as about 44 per 1,000 in the mid-1980s in a genuine “baby boom.”⁷

But that boom was a 1980s phenomenon. Its babies are now adults in their late thirties and forties. What survives into the present is not elevated fertility but momentum: that large cohort is currently moving through its own childbearing years, which props up the absolute number of births even as births per woman keep declining. The Khmer Rouge’s demographic fingerprint on Cambodia today is structural — a distorted age profile and a wave of population growth still working its way through the pyramid — not behavioural. Cambodians are not having more children because of the genocide. They are simply numerous enough, in the prime childbearing band, to keep the maternity wards busy a while longer.

The dividend, and the deadline

That same momentum is, for now, Cambodia’s biggest economic asset. With a median age of around 28 and a large working-age share relative to dependents, the country sits in the sweet spot economists call the “demographic dividend” — the window when a falling birth rate has shrunk the number of children to support but ageing has not yet swelled the number of retirees. Get policy right during this window — jobs, schooling, savings, health — and the bulge of workers can power a burst of growth. The Ministry of Planning’s own brief frames it precisely this way: a “window of opportunity for economic benefits if strategic investments are made now, before ageing sets in.”²

The deadline is the catch. Windows close. Cambodians aged 60 and over numbered about 849,000, or 6.3% of the population, in 2008; by 2024 that had risen to roughly 1.75 million, or 10.1%.² By 2050 the same brief projects the over-60 share will exceed 23% — more than doubling again — as the total population grows to around 22 million and fertility slips below replacement. The youth bulge that looks like an asset today is, on a long enough timeline, a bill: today’s workers are tomorrow’s retirees, and a country that has not built wealth and pension capacity by the time they arrive inherits the obligations without the means.

Thailand is the warning

What that failure looks like is visible across the border. Thailand’s fertility rate dropped below replacement in 1991 — strikingly early for a country that was neither rich nor highly educated at the time — and it has stayed there for a full generation.¹¹ Deaths have exceeded births since around 2021, and in 2024 Thailand was formally classed a “fully aged society,” with people over 60 making up 20.69% of the population.¹³ Its working-age population is projected to shrink from about 43.2 million in 2020 to 36.5 million by 2040, and the World Bank estimates that demographic change alone will account for more than half of the projected decline in Thailand’s long-run growth between 2020 and 2050.¹⁴

The phrase development economists use is “growing old before growing rich” — the trap of ageing rapidly while still at middle-income levels, without the wealth and institutions that richer ageing societies built first.¹⁵ Where Japan and Germany aged as high-income countries, Thailand is doing it on a fraction of the income, with pension and healthcare costs for the elderly projected to climb from 6.2% of GDP in 2020 toward 11.3% by 2060.¹⁴¹⁷ Thailand is the cautionary version of Cambodia’s own future — and it reached this point from a demographic profile not unlike Cambodia’s today.

The same road, with a smaller head start

The uncomfortable comparison is in the income column. Thailand is ageing with a GDP per capita of roughly US$7,300 (about US$21,700 at purchasing-power parity).¹⁶ Cambodia, heading down the same demographic road, currently sits at around US$2,600 (about US$7,000 PPP) — roughly a third of Thailand’s level.⁹¹⁰ Cambodia only reached lower-middle-income status in 2015 and has set itself the goal of becoming high-income by 2050 — the very year its fertility is projected to fall below replacement and its ageing to accelerate.⁸ Its human capital base is thin for the task: the World Bank estimates a child born in Cambodia will grow up to be only about 49% as productive as they could be with full health and education.⁸

Indicator	Cambodia	Thailand
Total fertility rate (latest)	~2.5 (2025)	~0.9–1.4 (2025)
Fell below replacement	Not yet (projected ~2050)	1991
Median age	~28	~40
Population aged 60+	10.1% (2024)	20.7% (2024)
GDP per capita, nominal	~US$2,600 (2024)	~US$7,300 (2024)
GDP per capita, PPP	~US$7,000 (2024)	~US$21,700 (2024)
Demographic stage	Dividend window open	Fully aged society

The point is not that Cambodia is doomed to repeat Thailand’s path. It is that the two countries are at different points on the same curve, and Cambodia is approaching the ageing phase with a markedly smaller financial cushion. Its advantage is time — the dividend window is open now, not in hindsight — and the size of that advantage is exactly what is at stake. The risk for Cambodia was never a birth rate that is too high. It is the opposite: a birth rate falling quickly enough that the country could run short of young workers before it has built the wealth to support its old. The window is the asset. Whether it gets used is the open question.

Sources

1. World Bank, “Fertility rate, total (births per woman) – Cambodia.” Link
2. Ministry of Planning of Cambodia / UNFPA, “Policy Brief: Planning for Cambodia’s Evolving Population Dynamics” (July 2025). Link
3. Statbase (UN DESA data), “Fertility rate – Cambodia (1950–2025).” Link
4. PLOS Global Public Health, “Determinants of modern contraceptive use… in Cambodia” (2021–22 CDHS analysis, 2025). Link
5. Population Reference Bureau, “Recent Fertility and Family Planning Trends in Cambodia.” Link
6. Heuveline et al., “Fertility Rates in Cambodia: A Bumpy Road,” Fertility & Reproduction (World Scientific). Link
7. UN Statistics Division, “Fertility Trends in Cambodia.” Link
8. World Bank, “Cambodia — Country Overview” (lower-middle-income status, high-income 2050 goal, human capital index, rural development). Link
9. World Bank, “GDP per capita (current US$) – Cambodia.” Link
10. World Bank, “GDP per capita, PPP (current international $) – Cambodia.” Link
11. Wikipedia, “Demographics of Thailand” (TFR 0.87 on national registration data; below replacement since 1991). Link
12. Macrotrends, “Thailand Fertility Rate (1950–2025)” (UN-based estimate ~1.44). Link
13. The Nation Thailand, “Thailand’s ageing society threatens fiscal collapse” (fully aged society 2024, 20.69% elderly). Link
14. Asia Daily, “Thailand’s Demographic Turning Point” (working-age decline; World Bank growth estimate; fiscal projections). Link
15. IMF, “Asia: At Risk of Growing Old before Becoming Rich?” Regional Economic Outlook (April 2017). Link
16. World Bank, “Thailand — Data” (GDP per capita, nominal and PPP, 2024). Link
17. Thailand Business News / Krungsri Research, “Thailand’s aging population…” (UN aged-society categories; “old before rich”). Link
18. Featured image by Mikhail Nilov: https://www.pexels.com/photo/pregnant-woman-holding-a-laptop-7780877/