Negative population growth occurs when a country or region loses more people than it gains, causing its total population to shrink over time. This happens when deaths and emigration together outnumber births and immigration. While global population is still growing, dozens of countries are already experiencing this decline, and the United Nations projects the world’s population will peak in the mid-2080s at around 10.3 billion before beginning to fall.
How Population Growth Is Calculated
A country’s population change comes down to a simple equation: the number of births minus the number of deaths, plus net migration (people moving in minus people moving out). When that total is negative, the population shrinks. Each of these three components can push the number in either direction. A country with a healthy birth rate can still lose population if enough people emigrate. A country with almost no immigration can still grow if births far outpace deaths.
The critical benchmark is the replacement-level fertility rate: roughly 2.1 children per woman. That’s the number needed for a generation to exactly replace itself, with the extra 0.1 accounting for children who don’t survive to adulthood. When a country’s fertility rate falls below 2.1 and stays there, population decline becomes likely within a generation or two, unless immigration fills the gap. In the United States, the fertility rate has been below replacement almost continuously since 1971 and consistently below it since 2007.
Why Populations Start Shrinking
The most common driver is falling birth rates. As countries industrialize and living standards rise, families tend to have fewer children. Better access to contraception, higher education levels (especially among women), rising childcare costs, and urbanization all contribute. This pattern is so consistent across history that demographers call it the “demographic transition,” a predictable shift from high birth and death rates to low birth and death rates as societies modernize.
What happens after that transition completes is less certain. Some researchers, including demographers Mikko Myrskylä, Hans-Peter Kohler, and Francesco Billari, have suggested that fertility might tick back up at very high levels of development. But if it stays below 2.1, long-term population decline is inevitable without sustained immigration.
Emigration is the other major factor. Countries like Lithuania, Venezuela, and Zimbabwe have experienced significant population loss as people leave in search of better economic opportunities or flee conflict. In Lithuania, steady outward migration to wealthier European Union countries has compounded an already low birth rate, accelerating the decline. Syria lost millions of residents to displacement during its civil war. Eastern Europe saw especially volatile migration patterns over the past two decades, with some areas losing as many as 20 people per 1,000 residents in a single year to outward migration.
Countries Already in Decline
Japan is the most frequently cited example. Its population peaked around 2010 and has been falling since, driven by one of the lowest fertility rates in the world and very little immigration. South Korea, Italy, Greece, and several Eastern European nations face similar trajectories. In many of these countries, the population is not just shrinking but aging rapidly, meaning the share of elderly residents grows while the working-age population contracts.
China’s population began declining in 2022 after decades of growth, a shift with enormous global implications given its size. India surpassed China as the world’s most populous country in 2023, but its own fertility rate is now near or below replacement level, meaning its growth will slow significantly in coming decades.
Economic Consequences
A shrinking population creates a specific set of economic pressures. Fewer working-age people means a smaller labor force generating tax revenue, while a growing share of retirees increases demand for pensions and healthcare. Research from the Center for Global Development found that negative working-age population growth is associated with lower economic growth overall, declining government revenues, reduced investment returns, and depressed stock market performance.
The fiscal math gets difficult quickly. Health and pension spending rises just as the tax base contracts, creating structural budget deficits that are hard to close without either cutting benefits or raising taxes on a smaller pool of workers. Countries may also see lower interest rates and weaker consumer demand simply because there are fewer people buying homes, cars, and everyday goods. Sectors that already have low productivity growth, like elder care, see rising demand, which can drag on overall economic efficiency.
Environmental Upside
Population decline does carry potential environmental benefits. Fewer people generally means lower total carbon emissions, reduced resource consumption, and less pressure on ecosystems and biodiversity. Research published in Frontiers in Public Health noted that smaller populations provide environmental advantages through changes in total population size, age structure, and economic output. Lower fertility rates are also associated with higher income per capita, which can improve individual wellbeing even as the total economy grows more slowly.
These benefits aren’t automatic, though. A smaller but wealthier population that consumes more per person could offset some of the gains from having fewer people overall.
Can Countries Reverse the Trend?
Many governments have tried. Pronatalist policies, programs designed to encourage people to have more children, range from cash payments for each birth to subsidized childcare and extended parental leave. The results have been mixed at best.
Cash benefits appear to be the most effective tool, but the amount matters enormously. Countries like Australia, France, and Hungary spend over 1.3% of their GDP on family cash benefits. Japan and South Korea spend less than 1%. A recent analysis found that Japan’s current cash benefit levels have only about a 12% chance of reversing its fertility decline by 2030. But if Japan increased those benefits to match Australia’s or Hungary’s levels, the probability of reversal could rise to around 70% to 79%. The takeaway: modest incentives don’t move the needle. Only substantial, sustained financial support has a realistic chance of changing family size decisions, and even then, success isn’t guaranteed.
Immigration is the faster and more reliable way to offset population decline. Countries like Australia, Canada, and the United States have historically used immigration to maintain or grow their working-age populations even as native-born fertility rates fall. This approach brings its own political and social complexities, but demographically, it works. Net migration was positive over the past two decades across Australia, North America, and parts of Western Europe, all regions that attracted both job seekers and asylum seekers in significant numbers.
The Global Picture
The world is still decades away from overall population decline. The UN projects growth will continue until the mid-2080s, when the global population will reach roughly 10.3 billion before beginning a slow descent to about 10.2 billion by 2100. But this global number masks enormous regional variation. Sub-Saharan Africa will account for most of the remaining growth, while Europe, East Asia, and parts of Latin America are already shrinking or will be soon.
Negative population growth is not a crisis in itself. It’s a structural shift that creates both problems and opportunities. The countries that manage it well will be those that adapt their economies, pension systems, and immigration policies to a reality where there are simply fewer people each year. The ones that don’t will face mounting fiscal pressure, labor shortages, and the slow hollowing out of communities as young people leave regions where opportunity is contracting along with the population.