For decades, policymakers and researchers worried about overpopulation. Yet across much of the world, fertility rates have fallen below replacement levels. This shift raises important questions about population ageing, shrinking workforces, and the long-term sustainability of economic and social systems.
This visual story explores how the global fertility collapse could reshape society over the coming decades.
Global fertility rates have been falling for more than half a century.
Global fertility has fallen dramatically since 1960. What once looked like a world defined by rapid population growth is now shifting toward a very different demographic future. The global average has moved closer to replacement level, showing that fertility decline is not a short-term event but a long-term structural change. This opening chart establishes the central tension of the story: while much public discussion still focuses on population growth, many countries are already moving toward population stagnation or decline.
Many countries now have fertility rates below the level needed to maintain population size without migration.
The replacement line shows why this decline matters. A fertility rate of about 2.1 births per woman is commonly used as the level required to maintain population size without migration. Several major economies are now below this level, including some of the world’s most influential industrial nations. This means the issue is no longer theoretical. For these countries, the question is not whether fertility will fall, but how governments, workplaces and communities will adapt to smaller future generations.
Fertility decline is now visible across multiple regions, not just in wealthy countries.
The regional trends show that fertility decline is not confined to one part of the world. While Europe, North America and East Asia reached low fertility earlier, other regions have also experienced substantial declines over time. This matters because it suggests the fertility shift is connected to broad social and economic changes, including urbanisation, education, healthcare access and changing family expectations. The story is therefore not just about a few wealthy countries, but about a global demographic transition.
The countries with the world’s lowest fertility rates are also among the oldest societies on Earth.
Low fertility becomes especially important when it is combined with population ageing. Countries with lower birth rates often have a growing share of people aged 65 and over, meaning fewer workers may be available to support more retirees. This creates pressure on healthcare systems, pensions, aged care, taxation and labour markets. The issue is not simply that fewer children are being born, but that the structure of society changes when older age groups become a larger share of the population. # Chart 5: The Empty Future
The challenge may not be population size itself, but the changing balance between workers and retirees.
The long-term challenge of fertility decline is not simply slower population growth. Instead, it is the changing balance between younger and older generations. As fertility falls and life expectancy increases, the proportion of working-age adults is expected to shrink while the share of elderly citizens grows. This shift could reshape labour markets, public finances, housing demand and social welfare systems. The demographic future may therefore be defined less by how many people exist and more by the age structure of society itself.
The global fertility decline represents one of the most significant demographic shifts of the modern era. While concerns about overpopulation dominated much of the twentieth century, many countries now face a different challenge: sustaining economic growth and social stability with fewer births and ageing populations. The trends shown throughout this story suggest that fertility decline is no longer confined to a handful of wealthy nations but is increasingly becoming a global phenomenon. If current patterns continue, governments, businesses and communities may need to rethink how societies are structured, how workforces are maintained, and how future generations are supported. The demographic future may therefore be shaped not by population growth, but by population balance.
#References
World Bank. (2025). Fertility rate, total (births per woman) (SP.DYN.TFRT.IN). World Bank Open Data. https://data.worldbank.org/indicator/SP.DYN.TFRT.IN
World Bank. (2025). Population ages 65 and above (% of total population) (SP.POP.65UP.TO.ZS). World Bank Open Data. https://data.worldbank.org/indicator/SP.POP.65UP.TO.ZS
United Nations World Population Prospects 2024. (2024). World population prospects 2024. United Nations Department of Economic and Social Affairs.
United Nations World Fertility Report 2024. (2024). World fertility report 2024. United Nations Department of Economic and Social Affairs.
OECD Fertility Rates Database. (2025). Fertility rates. Organisation for Economic Co-operation and Development.
The Conversation. (2025). The Conversation style guide and editorial approach.