Population decline facts for kids

Population decline, also known as depopulation, means when the number of people in a population goes down. For most of history, the total number of people on Earth kept growing. But now, experts think this long-term growth might be ending.

For a very long time, until the Industrial Revolution began, the world's population grew very slowly. After 1800, it started growing much faster. It reached its fastest growth between 1962 and 1968. Since then, the growth has slowed down a lot. This is because the number of children women are having has dropped worldwide.

Experts predict that the world's population growth will keep slowing down. They think it might even stop growing completely before the end of this century. For example, Japan's population is already shrinking. China's population has also started to decline. By 2050, Europe's population is expected to be shrinking too.

The main reason for this slowdown is that the average number of children per woman has fallen sharply. In 1963, it was 5.3 children, but in 2021, it was only 2.3. This drop in birth rates has happened all over the world. It is part of a process called demographic transition. To keep its population stable, a country needs women to have about 2.1 children on average. This number is a bit more than 2 because not all children live to become adults. However, in wealthier countries, women tend to have fewer children, often well below 2.

There are many reasons why women in richer countries have fewer children. For example, fewer babies die young. Also, families don't need as many children for farm work or to support parents when they get old. Better education for young women also plays a big part. It gives them more job choices.

The long-term effects of a country's population shrinking can be good or bad. If a country's workers can produce more goods and services faster than its population shrinks, things can be positive. This means a better economy, better lives for people, and a healthier environment. But if productivity doesn't grow fast enough, the results can be negative.

So far, countries trying to deal with shrinking populations have focused on the possible bad effects on their economies. They mostly try to make their workforce bigger and more productive.

What Makes Populations Decline?

A population shrinking over time can happen because of sudden bad events. These include outbreaks of disease, famine (when there isn't enough food), or war. It can also be caused by long-term trends. These trends include women having fewer children than needed to replace the population, low birth rates, high mortality rates (death rates), or many people moving away (emigration).

Sudden Population Drops

Collapse of population in Mexico during the 16th century, attributed to repeated epidemics of smallpox and cocoliztli

Throughout history, there have been many times when human populations suddenly dropped. Several things caused these short-term declines.

High death rates were caused by:

• Diseases: For example, the Black Death in Europe in the 14th and 17th centuries. Also, diseases from Europe arrived in the Americas during colonization. The Spanish flu pandemic after World War I also caused many deaths.
• Famine: The Great Irish Famine in the 19th century is one example. The Great Chinese Famine caused by the Great Leap Forward also led to millions of deaths.
• War: The Mongol invasion of Europe in the 13th century might have cut Hungary's population by 20–40%.
• Civil unrest: For instance, many people were forced to leave Syria because of the civil war.
• A mix of these: In Imperial Russia and the Soviet Union during the first half of the 20th century, many wars, famines, and other disasters caused huge population losses. About 60 million more people died than usual.

Sometimes, short-term population drops are caused by genocide or mass killings. For example, the Armenian genocide caused about 1.5 million deaths. The Jewish Holocaust caused about 6 million deaths. In the 1970s, Cambodia's population fell because of widespread executions by the Khmer Rouge.

More recently, the AIDS pandemic and the COVID-19 pandemic caused short-term drops in birth rates. They also led to many more deaths than usual in some countries.

Some population declines happen for unknown reasons. The Late Bronze Age collapse, for example, is called the worst disaster in ancient history.

Long-Term World Population Trends

Even with these sudden drops, the world population has kept growing. From about 10,000 BC until the Early modern period (around 1500–1800), the world population grew very slowly. It was stuck in what is called the “Malthusian trap”.

After 1700, things changed. The Industrial Revolution led to people producing much more, especially in farming. This made population growth speed up a lot. It grew over ten times faster than in the previous 12,000 years. This fast growth made people like Malthus worry about too many people.

After World War I, birth rates in the United States and many European countries fell. They went below the level needed to replace the population. This caused worries about population decline. But around 1940, birth rates in most Western countries went up again. This led to the "baby boom." Growth rates were high, peaking between 1962 and 1968. This made people stop worrying about population decline for a while. Instead, they were again afraid of overpopulation.

Map of countries by fertility rate (2023), according to the Population Reference Bureau

However, after 1968, the global population growth rate started to slow down. Between 2022 and 2027, the UN estimates it to be less than half of its peak. While the population is still growing, the UN predicts it will level off around 2086. Some sources even think it will start declining before then.

The main reason for this is the sharp drop in the global total fertility rate. It went from 5.3 in 1963 to 2.3 in 2021. This happened as the world moved through the different stages of the Demographic Transition. The drop in birth rates has happened everywhere. This has brought new worries about population decline from some people.

The time of rapid global population growth, and worries about a "population explosion," has been short. It started with the Industrial Revolution and now seems to be ending.

What Could Happen?

It's hard to predict the exact economic effects of a slow, continuous population decline. This is because it's a new situation. Studies show that population growth usually has a small effect on economic growth. This effect can be positive, negative, or none at all. A recent study found no link between population growth and economic growth.

Good Things That Could Happen

A shrinking population can have good effects. The best way to measure economic success is how much money is made per person, not the total money made. Money made per person (also called GDP per capita) shows the average living standard. A country can increase its average living standard and total money made, even if its population growth is low or negative.

For example, the economies of both Japan and Germany started to recover around the time their populations began to shrink (2003–2006). This means that both the total and per person money made grew faster after 2005. Russia's economy also grew quickly from 1999, even though its population had been shrinking since 1992–93. Many Eastern European countries have seen similar results. This new growth makes people question the old idea that economic growth needs population growth.

More recently (2009–2017), Japan's money made per person grew more than in the United States. This happened even though Japan's population declined. In the United States, there's no clear link between population growth and money made per person. This shows that people can become more prosperous even when the population shrinks.

When a country focuses on making its workers more productive, it can lead to many benefits:

• Workers get higher wages, better benefits, and improved working conditions.
• Customers get lower prices.
• Business owners and shareholders get higher profits.
• The environment benefits from more money for protection.
• Governments get more tax money to fund public services.

Another way to look at positive effects is to think about Earth's human carrying capacity. This is the maximum number of people the Earth can support. A global population decline would help reduce the negative effects of human overpopulation. There have been many guesses about Earth's carrying capacity. Most predict a range of possible maximum human populations. The lowest guess is less than one billion, and the highest is over one trillion. One study found that the average high guess was 12 billion, and the average low guess was about 8 billion. This suggests our planet might be reaching its limit for human population. However, these guesses vary a lot, so it's hard to be sure.

Bad Things That Could Happen

A shrinking population can also have negative effects. As a country's population declines, its total money made (GDP) might grow even slower or even shrink. If the population decline is not balanced by workers becoming more productive, the country could face an economic recession. If this continues, the country could be in a permanent recession.

Other possible negative effects of a shrinking population include:

• More older people relying on fewer working people. This puts more economic pressure on the workforce.
• A loss of culture and less trust among people.
• Problems with caring for the elderly because there aren't enough caregivers.
• Difficulty funding programs for retirees because there are fewer workers compared to retirees.
• A decrease in military strength.
• Less new ideas and inventions, as change often comes from young people.
• Mental health strain caused by ongoing economic problems.
• Falling prices (deflation) caused by an aging population.

All these negative effects can be summed up as "Underpopulation." This usually means a country's population has shrunk too much to support its current economic system.

Population decline can also cause problems within a country. These can lead to ethnic conflict, forced movement of people (refugees), and extreme nationalism. This is especially true when different groups in a country have different growth rates. Low birth rates that cause long-term population decline can also lead to population aging. This means there are too many older people compared to younger people. Population aging in Europe has raised worries about its effect on how well society works together.

A smaller national population can also affect a country's power in the world. But the link between population and power is not always strong. Technology and resources often play bigger roles. After World War II, people thought a country's size was a key part of its power. More recently, the "human capital" idea has become popular. This idea says that the quality and skills of workers, along with available technology and resources, are more important than just population size. While having many children used to be an advantage, that "demographic dividend" has mostly disappeared.

How Countries Deal with Shrinking Populations

A country with a shrinking population will find it hard to pay for public services. These include healthcare, benefits for older people, defense, education, and water systems. To keep its economy growing and improve people's lives, a country facing population decline will focus on the threat of a shrinking economy. Since a country's economy depends on the size and productivity of its workforce, it will try to make its workforce bigger and more productive.

Making the Workforce Bigger

A country's workforce is the part of its working-age population that has jobs. Working age is usually considered to be people aged 15–64.

Policies that could make the workforce bigger include:

• Natalism:

Natalism means government policies and cultural changes that encourage people to have more children. These usually fall into three main types: * Money help: This can include child benefits and other government payments that help families pay for children. * Support for parents to work and raise a family: This includes paid time off for new mothers and fathers. It also includes childcare services. * General social changes: These changes encourage having children and being a parent.

For example, Sweden built a large welfare state from the 1930s. This was partly because of a debate after a book called "Crisis in the Population Question" came out in 1934. Today (2017), Sweden has long parental leave. Parents can share 16 months of paid leave per child. The cost is split between employers and the government.

Other examples include Romania's natalist policy from 1967–90 and Poland's 500+ program.

• Encourage more women to join the workforce:

Getting more women who are of working age but not working to find jobs would make the workforce bigger. Currently (2018), fewer women work than men in almost all countries. In developed countries, the gap between men and women in the workforce can be very wide. For example, in South Korea (2018), 59% of women work compared to 79% of men.

However, even if more women want to work, increasing their participation would only help for a short time. Eventually, a limit is reached, and further increases are not possible. Then, the effect on economic growth stops.

• Stop the decline of men in the workforce:

In the United States, fewer men have been working since the late 1960s. The labor force participation rate is the number of people working compared to the total working-age population. In 1969, 96% of men aged 25–54 were working. In 2015, this was under 89%.

• Raise the retirement age:

Raising the age when people can retire makes the working-age population bigger. But to actually make the workforce bigger, other changes are needed: * Pension reform: Many retirement rules encourage people to retire early. For example, in 2018, less than 10% of Europeans aged 64–74 were working. Many public pension plans limit how much older people can earn if they work. * Workplace culture changes: Employers need to change their attitudes towards older workers. To keep older people working longer, there needs to be investment in training and better working conditions.

One study estimated that raising the retirement age by 2–3 years each decade between 2010 and 2050 would help countries like Germany and Japan deal with their shrinking working-age populations.

• Increase immigration:

A country can make its workforce bigger by bringing in more immigrants who are of working age. Even if the local workforce is shrinking, skilled immigrants can slow down or even reverse this decline. However, this only works if immigrants can find jobs and if the local population accepts them.

For example, starting in 2019, Japan, a country with a shrinking workforce, allowed 250,000 unskilled guest workers to get five-year visas. This new rule made between 260,000 and 345,000 five-year visas available for workers in 14 areas with severe worker shortages. These included caregiving, construction, farming, and shipbuilding.

• Reduce emigration:

Many people moving away from a country for a long time, often called "Brain Drain," can be a major cause of population decline. However, research has also found that people leaving a country can sometimes have good effects on the country they left. So, this argues against trying to stop people from leaving.

Making the Workforce More Productive

Economists call making the workforce bigger "extensive growth." They call making the workforce more productive "intensive growth." In this case, economic growth comes from each worker producing more. This also means more money made per person.

When a population is stable or shrinking, making the workforce more productive is better than short-term efforts to make it bigger. Economic ideas suggest that in the long run, most growth will come from intensive growth. This means new technology, better ways of doing things, and more money and education to spread these improvements to workers.

Making the workforce more productive through intensive growth only works if workers who lose jobs because of new technology can be retrained. This helps them keep their skills current and not be left behind. Otherwise, it leads to technological unemployment. Money for worker retraining could come from a "robot tax," though this idea is debated.

Future Trends

A long-term population decline usually happens when women have fewer children than needed to replace the population. It also happens when not enough immigrants arrive to make up for more deaths than births. A long-term decline also leads to population aging. This means there are more retirees compared to workers and children. If the birth rate stays low, population decline speeds up over time.

Because the global birth rate is falling, predictions for the future global population show growth slowing down a lot. There is also the possibility of a long-term decline.

The table below summarizes the United Nations' predictions for future population growth. Any such long-term predictions are just guesses. The UN divides the world into six regions. Their predictions show that between 2045–2050, Europe's population will be shrinking. All other regions will see much slower growth. By the end of the 21st century (2095–2100), three of these regions will have shrinking populations. The global population will have peaked and started to decline.

Note: The UN explains how they made these numbers in their reference materials.

The table shows UN predictions of long-term decline in population growth rates everywhere. However, short-term baby booms and better healthcare can sometimes reverse these trends. Population declines in Russia (1994–2008), Germany (1974–1984), and Ireland (1850–1961) have all seen long-term reversals. The UK, which had almost no growth between 1975–1985, is now (2015–2020) growing at 0.6% per year.

See also

• Zero population growth
• Birth dearth
• History of Easter Island#Destruction of society and population
• Human extinction
• Human overpopulation
• Human population planning
• Negative Population Growth
• Political demography
• Population cycle
• Population growth
• Rural flight
• Societal collapse
• Antinatalism