Will Low Fertility Rates Return to Replacement Level Soon?

Currently, more than half of all countries and areas worldwide have a fertility rate below the replacement level of 2.1 births per woman.

Will low fertility rates return to the replacement level of 2.1 births per woman any time soon? The simple answer to this vital demographic question is: unlikely.

A more detailed answer involves the complex interaction of economic, social, developmental, cultural and personal factors that influence fertility levels.

These factors include economic insecurity, financial pressures, marriage rates, age at childbearing, child mortality, contraceptive use, higher education, labour force participation, lifestyle choices, personal goals, concerns about the future, and difficulties in finding a suitable spouse or partner for family life.

In recent decades, the world’s fertility rate has declined sharply, falling from 5.3 births per woman in 1963 to 2.3 births in 2023.

Currently, more than half of all countries and territories worldwide have fertility rates below the replacement level of 2.1 births per woman. Among them are the world’s ten largest national economies.

By contrast, many sub-Saharan African countries continue to record high fertility rates. Together, these countries account for about one-third of the world’s annual births, a share projected to rise to nearly 40 percent by mid-century.

At present, around two dozen sub-Saharan African countries have fertility rates of four or more births per woman, with about half recording five or more. Countries such as Chad, the Democratic Republic of the Congo and Somalia have some of the highest fertility rates globally, at around six births per woman.

In low-fertility countries, many young adults increasingly prioritise economic security over starting a family. This shift reflects the high financial burden of housing, food, transportation, childcare and education.

The cost of raising a child varies widely across countries due to differences in income levels, family structures, living expenses and government support. However, couples generally perceive child-rearing as a demanding and costly undertaking.

Another important factor is the rising age at marriage and childbearing. Globally, early childbearing has declined, and in more developed regions — as well as in many developing countries such as China and India — the average age of childbearing has increased by about three years since 1995.

Declines in teenage pregnancies have also contributed to lower fertility. Between 1994 and 2024, the global adolescent birth rate fell from 74 to 38 births per 1,000 females aged 15 to 19.

In addition to delaying childbirth, many women are having fewer children, with a growing share choosing not to have children at all. In developed countries, around 40 percent or more of women remain childless by age 30.

The widespread use of contraception is another major contributor to low fertility. In 2022, about half of women of reproductive age worldwide were estimated to be using contraceptives, with roughly 90 percent relying on modern methods.

Higher education and increased female labour force participation also play a significant role. These trends raise the opportunity cost of childbearing, encourage later marriage and parenthood, and shift priorities towards careers and personal development.

Over the past 50 years, women’s enrolment in higher education has risen globally. Women now form the majority of higher education students in 114 countries, while men outnumber women in 57. At the bachelor’s degree level, women have largely reached parity with men.

In many low-fertility countries, female participation in the workforce has increased markedly. In Spain, for example, the share of women in the labour force has more than doubled over the past five decades, rising from about one in four to more than half.

Sharp declines in infant and child mortality have also reduced fertility. Over the past 50 years, the global infant mortality rate fell from about 90 deaths per 1,000 births to 27, while under-five mortality declined from 132 to 36 deaths per 1,000 live births.

As a result of sustained low fertility, many countries now record more deaths than births, leading to population decline and demographic ageing.

In response, governments in low-fertility countries have introduced pro-natalist policies and incentives. While such measures may slightly raise birth rates, historical experience shows that once fertility falls below replacement level — especially below 1.5 births per woman — it tends to remain low.

Population projections indicate that fertility rates in most low-fertility countries are unlikely to return to replacement level in the near future. Globally, fertility is expected to continue declining throughout the 21st century, reaching an estimated 1.8 births per woman by 2100.

Many countries are projected to experience population decline by mid-century, even after accounting for immigration. In around 50 countries and territories, international migration is expected to partially offset population losses caused by low fertility.

Immigration levels have reached record highs in several countries. In the European Union, foreign-born residents account for about 14 percent of the population, up from 10 percent in 2010. In the United States, the foreign-born share stands at nearly 16 percent, compared with a low of 5 percent in 1970. Canada’s foreign-born population now makes up nearly one-quarter of its total population, while Australia’s has approached one-third.

Alongside population decline and rising immigration, many countries are also experiencing rapid population ageing. Once youthful populations are being replaced by older ones, with growing proportions reaching retirement age.

In summary, given current global trends and the powerful economic, social and personal factors at play, a return of low fertility rates to replacement level appears unlikely any time soon. Countries will need to adapt to future demographic realities rather than expect a return to the patterns of the recent past.

Joseph Chamie is a consulting demographer, former director of the United Nations Population Division, and author of numerous publications on population issues.