Birth Rate Decline

Population decline, also known as depopulation, is a reduction in a human population size. Throughout history, Earth's total human population has continued to grow but projections suggest this long-term trend may be coming to an end.

From antiquity until the beginning of the Industrial Revolution, the global population grew very slowly, at about 0.04% per year. After about 1800, the growth rate accelerated to a peak of 2.1% annually during the 1962–1968 period, but since then, due to the worldwide collapse of the total fertility rate, it has slowed to 0.9% as of 2023. The global growth rate in absolute numbers accelerated to a peak of 92.8 million in 1990, but has since slowed to 70.4 million in 2023.

Long-term projections indicate that the growth rate of the human population of the planet will continue to slow and that before the end of the 21st century, it will reach zero. Examples of this emerging trend are Japan, whose population is currently (2023) declining at the rate of 0.5% per year, and China, whose population has peaked and is currently (2023) declining at the rate of about 0.2% per year. By 2050, Europe's population is projected to be declining at the rate of 0.3% per year.

Population growth has declined mainly due to the abrupt decline in the global total fertility rate, from 5.3 in 1963 to 2.2 in 2023. The decline in the total fertility rate has occurred in every region of the world and is a result of a process known as demographic transition. To maintain its population, ignoring migration, a country on average requires a minimum fertility rate of 2.2 children per woman of childbearing age (the number is slightly greater than two because not all children live to adulthood). However, most societies experience a drop in fertility to well below two as they grow more wealthy.

The tendency of women in wealthier countries to have fewer children is attributed to a variety of reasons, such as lower infant mortality and a reduced need for children as a source of family labor or retirement welfare, both of which reduce the incentive to have many children. Better access to education for young women, which broadens their job prospects, is also often cited.

Possible consequences of long-term national population decline can be net negative or positive. If a country can increase its workforce productivity faster than its population is declining, the results, in terms of its economy, the quality of life of its citizens, and the environment, can be net positive. If it cannot increase workforce productivity faster than its population's decline, the results can be negative.

National efforts to confront a declining population to date have been focused on the possible negative economic consequences and have been centered on increasing the size and productivity of the workforce.

Causes

A reduction over time in a region's population can be caused by sudden adverse events such as outbursts of infectious disease, famine, and war or by long-term trends, for example, sub-replacement fertility, persistently low birth rates, high mortality rates, and continued emigration.

Short-term population shocks

Historical episodes of short-term human population decline have been common and have been caused by several factors.

High mortality rates caused by:

* Disease, for example, the Black Death that devastated Europe in the 14th and 17th centuries, the arrival of Old World diseases in the Americas during European colonization, and the Spanish flu pandemic after World War I,
* Famine, for example, the Great Irish Famine of the 19th century, and the Great Chinese Famine caused by the Great Leap Forward which caused tens of millions of deaths,
* War, for example, the Mongol invasion of Europe in the 13th century, which may have reduced the population of Hungary by 20–40%,
* Civil unrest, for example, the forced migration of the population of Syria because of the Syrian Civil War.
* A combination of these. The first half of the 20th century in Imperial Russia and the Soviet Union was marked by a succession of major wars, famines and other disasters which caused large-scale population losses (approximately 60 million excess deaths).

Less frequently, short-term population declines are caused by genocide or mass execution. For example, it has been estimated that the Armenian genocide caused 1.5 million deaths, the Jewish Holocaust about 6 million, and, during the period 1975 - 1979, the population of Cambodia declined 26% because of wide-scale executions by the Khmer Rouge.

In modern times, the AIDS pandemic and the COVID-19 pandemic have caused short-term drops in fertility and significant excess mortality in a number of countries.

Some population declines result from indeterminate causes, for example, the Bronze Age Collapse, which has been described as the worst disaster in ancient history.

Long-term historic trends in world population growth

In spite of these short-term population shocks, world population has continued to grow. From around 10,000 BC to the beginning of the Early modern period (generally 1500 – 1800), world population grew very slowly, around 0.04% per year. During that period, population growth was governed by conditions now labeled the “Malthusian Trap”.

After 1700, driven by increases in human productivity due to the Industrial Revolution, particularly the increase in agricultural productivity, population growth accelerated to around 0.6% per year, a rate that was over ten times the rate of population growth of the previous 12,000 years. This rapid increase in global population caused Malthus and others to raise the first concerns about overpopulation.

After World War I birth rates in the United States and many European countries fell below replacement level. This prompted concern about population decline. The recovery of the birth rate in most western countries around 1940 that produced the "baby boom", with annual growth rates in the 1.0 – 1.5% range, and which peaked during the period 1962–1968 at 2.1% per year, temporarily dispelled prior concerns about population decline, and the world was once again fearful of overpopulation.

But after 1968 the global population growth rate started a long decline, and the United Nations Population Division (UN) has reported that in the year 2023 it had dropped to about 0.9%, less than half of its peak during the period 1962 – 1968. Although still growing, the UN predicts that global population will level out around 2084, and some sources predict the start of a decline before then.

The principal cause of this phenomenon is the abrupt decline in the global total fertility rate, from 5.3 in 1963 to 2.2 in 2023, as the world continues to move through the stages of the Demographic Transition. The decline in the total fertility rate has occurred in every region of the world and has brought renewed concern from some for population decline.

The era of rapid global population increase, and concomitant concern about a population explosion, has been short compared with the span of human history. It began roughly at the beginning of the industrial revolution and appears to be now drawing to a close.

Possible consequences

Predictions of the ''net'' economic (and other) effects from a slow and continuous population decline (e.g. due to low fertility rates) are mainly theoretical since such a phenomenon is a relatively new and unprecedented one. The results of many of these studies show that the estimated impact of population growth on economic growth is generally small and can be positive, negative, or nonexistent. A recent meta-study found no relationship between population growth and economic growth.

Possible positive effects

The effects of a declining population can be positive. The single best gauge of economic success is the growth of GDP per person, not total GDP. GDP per person (also known as GDP per capita or per capita GDP) is a rough proxy for average living standards. A country can both increase its average living standard and grow its total GDP even though its population growth is low or even negative. The economies of both Japan and Germany went into recovery around the time their populations began to decline (2003–2006). In other words, both the total and per capita GDP in both countries grew more rapidly after 2005 than before. Russia's economy also began to grow rapidly from 1999 onward, even though its population had been shrinking since 1992–93. Many Eastern European countries have been experiencing similar effects to Russia. Such renewed growth calls into question the conventional wisdom that economic growth requires population growth, or that economic growth is impossible during a population decline.

More recently (2009–2017) Japan has experienced a higher growth of GDP per capita than the United States, even though its population declined over that period. In the United States, the relationship between population growth and growth of GDP per capita has been found to be empirically insignificant. This evidence shows that individual prosperity can grow during periods of population decline.

Attempting to better understand the economic impact of these pluses and minuses, Lee et al. analyzed data from 40 countries. They found that typically fertility well above replacement and population growth would be most beneficial for government budgets. Fertility near replacement and population stability, however, would be most beneficial for standards of living when the analysis includes the effects of age structure on families as well as governments. Fertility moderately below replacement and population decline would maximize per capita consumption when the cost of providing capital for a growing labor force is taken into account.

A focus on productivity growth that leads to an increase in both per capita GDP and total GDP can bring other benefits to:

*the workforce through higher wages, benefits and better working conditions
*customers through lower prices
*owners and shareholders through higher profits
*the environment through more money for investment in more stringent environmental protection
*governments through higher tax proceeds to fund government activities

Another approach to possible positive effects of population decline is to consider Earth's human carrying capacity. Global population decline would begin to counteract the negative effects of human overpopulation. There have been many estimates of Earth's carrying capacity, each generally predicting a high-low range of maximum human population possible. The lowest low estimate is less than one billion, the highest high estimate is over one trillion. A statistical analysis of these historical estimates revealed that the median of high estimates of all of the ranges would be 12 billion, and the median of low estimates would be about 8 billion. According to this analysis, this planet may be entering a zone where its human carrying capacity could be exceeded. However, the large variance in these studies’ estimates diminishes our confidence in them, as such estimates are very difficult to make with current data and methods.

Possible negative effects

The effects of a declining population can also be negative. As a country's population declines, GDP growth may grow even more slowly or may even decline. If the decline in total population is not matched by an equal or greater increase in productivity (GDP/capita), and if that condition continues from one calendar quarter to the next, it follows that a country would experience a decline in GDP, known as an economic recession. If these conditions become permanent, the country could find itself in a permanent recession.

Other possible negative impacts of a declining population are:

* A rise in the dependency ratio which would increase the economic pressure on the workforce
* A loss of culture and the diminishment of trust among citizens
* A crisis in end-of-life care for the elderly because there are insufficient caregivers for them
* Difficulties in funding entitlement programs because there are fewer workers relative to retirees
* A decline in military strength
* A decline in innovation since change comes from the young
* A strain on mental health caused by permanent recession
* Deflation caused by the aging population

All these negative effects could be summarized under the heading of "Underpopulation".  Underpopulation is usually defined as a state in which a country's population has declined too much to support its current economic system.

Population decline can cause internal population pressures that then lead to secondary effects such as ethnic conflict, forced refugee flows, and hyper-nationalism. This is particularly true in regions where different ethnic or racial groups have different growth rates. Low fertility rates that cause long-term population decline can also lead to population aging, an imbalance in the population age structure. Population aging in Europe due to low fertility rates has given rise to concerns about its impact on social cohesion.

A smaller national population can also have geo-strategic effects, but the correlation between population and power is a tenuous one. Technology and resources often play more significant roles. Since World War II, the "static" theory saw a population's absolute size as being one of the components of a country's national power. More recently, the "human capital" theory has emerged. This view holds that the quality and skill level of a labor force and the technology and resources available to it are more important than simply a nation's population size. While there were in the past advantages to high fertility rates, that "demographic dividend" has now largely disappeared.

Contemporary decline by country

The table below shows the countries that have been affected by population decline between 2010 and 2020. The term "population" used here is based on the ''de facto'' definition of population, which counts all residents regardless of legal status or citizenship, except for refugees not permanently settled in the country of asylum, who are generally considered part of the population of the country of origin. This means that population growth in this table includes net changes from immigration and emigration. For a table of natural population changes, see the list of countries by natural increase.

Figure includes Abkhazia and South Ossetia.
Includes the Pridnestrovian Moldavian Republic.

East Asia

China

China's population peaked at 1.41 billion in 2021 and began declining in 2022. China recorded more deaths than births for the first time in 2022 with a net decrease of 850,000 and this trend continued in 2023 when deaths overnumbered births by a margin of more than 2 million and in 2024 with deaths overnumbering births by 1.4 million.

The UN's Population Division, assuming that China's total fertility rate will rise from 1 in 2022 to 1.34 by 2100, projects its population to be 633 million by 2100, a decline of about 56%.

Japan

Though Japan's natural increase turned negative as early as 2005, the 2010 census result figure was slightly higher, at just above 128 million, than the 2005 census. Factors implicated in the puzzling figures were more Japanese returnees than expected as well as changes in the methodology of data collection. However, the official count put the population as of October 1, 2015, at 127.1 million, down by 947,000 or 0.7% from the previous quinquennial census. The gender ratio is increasingly skewed; some 106 women per 100 men live in Japan. In 2019, Japan's population fell by a record-breaking 276,000; if immigration is excluded from the figures, the drop would have been 487,000. Given the population boom of the 1950s and 1960s, the total population is still 52% above 1950 levels.

The UN's Population Division, assuming that Japan's total fertility rate will rise from 1.2 in 2023 to 1.47 by 2100, projects its population to fall to 77 million by 2100, a decline of about 38%.^,

South Korea

South Korea's total fertility rate has been consistently lower than that of Japan, breaking below 1 in 2018, and fell to 0.778 in 2022. As a result, its population fell in 2020 for the first time in the country's history from 51.8 million in 2020 to 51.6 in 2022.

The UN's Population Division, assuming that South Korea's total fertility rate will rise from 0.72 in 2023 to 1.3 by 2100, projects its population to fall to nearly 22 million by 2100, a decline of about 58%.^,

Taiwan

Taiwan recorded more deaths than births for the first time in 2020, despite recording virtually no COVID-19 deaths, thus starting an era of demographic decline for the foreseeable future. Taiwan's population fell from 23.6 million in 2020 to 23.4 in 2023, while the total fertility rate decreased from 1.05 in 2020 to 0.85 in 2023.

The UN's Population Division, assuming that Taiwan's total fertility rate will rise from 0.87 in 2023 to 1.33 by 2100, projects its population to fall to 10 million by 2100, a decline of about 57%.^,

Thailand

Thailand's total fertility rate has been consistently lower than the replacement rate of 2.1 since the beginning of the 1990s and reached a new low in 2022, at 1. Thailand 's population decline started in 2020 and Thailand for the first time recorded more deaths than births in 2021. This negative natural population change amplified in 2022 and 2023 and, in the absence of substantial immigration, this trend will continue in the coming years due to the very low fertility rate.

Eastern Europe and former Soviet republics

Population in the ex-USSR and Eastern Europe is rapidly shrinking due to low birth rates, very high death rates (linked to alcoholism and high rates of infectious diseases such as AIDS and TB), as well as high emigration rates. In Russia and the former communist bloc, birth rates fell abruptly after the fall of the Soviet Union, and death rates generally rose sharply. In addition, in the 25 years after 1989, some 20 million people from Eastern Europe are estimated to have migrated to Western Europe or the United States.

Belarus

Belarus's population peaked at 10,151,806 in the 1989 Census and declined to 9,480,868 as of 2015 as estimated by the state statistical service. This represents a 7.1% decline since the peak census figure.

Estonia

In the last Soviet census of 1989, it had a population of 1,565,662, which was close to its peak population. The state statistics reported an estimate of 1,314,370 for 2016. This represents a 19.2% decline since the peak census figure.

Georgia

In the last Soviet census of 1989, it had a population of 5,400,841, which was close to its peak population. The state statistics reported an estimate of 4,010,000 for the 2014 Census, which includes estimated numbers for quasi-independent Abkhazia and South Ossetia. This represents a 25.7% decline since the peak census figure, but nevertheless somewhat higher than the 1950 population.

Latvia

When Latvia split from the Soviet Union, it had a population of 2,666,567, which was very close to its peak population. The latest census recorded a population of 2,067,887 in 2011, while the state statistics reported an estimate of 1,986,086 for 2015. This represents a 25.5% decline since the peak census figure, with only one of two nations worldwide falling below 1950 levels. The decline is caused by both a negative natural population growth (more deaths than births) and a negative net migration rate. As of 1 May 2024, Latvia had a total population of 1,862,700.

Lithuania

When Lithuania split from the Soviet Union, it had a population of 3.7 million, which was close to its peak population. The latest census recorded a population of 3.05 million in 2011, down from 3.4 million in 2001, further falling to 2,988,000 on September 1, 2012.
This represents a 23.8% decline since the peak census figure, and some 13.7% since 2001.

Ukraine

Ukraine census in 1989 resulted in 51,452,034 people. Ukraine's own estimates show a peak of 52,244,000 people in 1993; however, this number has plummeted to 45,439,822 as of December 1, 2013. Having lost Crimean territory to Russia in early 2014 and subsequently experiencing war, the population dropped to 42,981,850 as of August 2014. This represents a 19.7% decrease in total population since the peak figure, but 16.8% above the 1950 population even without Crimea. Its absolute total decline (9,263,000) since its peak population is the highest of all nations; this includes loss of territory and heavy net emigration. Eastern Ukraine may yet lose many Russian-speaking citizens due to the new Russian citizenship law. An editorial projects significant gender and age imbalance in the population in Ukraine as a substantial problem if most refugees, as in other cases, do not return over time. Approximately 3.8 million more people have left the country during the 2022 Russian invasion of Ukraine, and thousands have died in the conflict.

The Russian invasion of Ukraine considerably deepened the country's demographic crisis. The birth rate in Ukraine was 28% lower in the first six months of 2023 compared to the same period in 2021. A July 2023 study by the Vienna Institute for International Economic Studies stated that " gardless of how long the war lasts and whether or not there is further military escalation, Ukraine is unlikely to recover demographically from the consequences of the war. Even in 2040 it will have only about 35 million inhabitants, around 20% fewer than before the war (2021: 42.8 million) and the decline in the working-age population is likely to be the most severe and far-reaching."

Hungary

Hungary's population peaked in 1980, at 10,709,000, and has continued its decline to under 10 million as of August 2010. This represents a decline of 7.1% since its peak; however, compared to neighbors situated to the East, Hungary peaked almost a decade earlier yet the rate has been far more modest, averaging −0.23% a year over the period.

Balkans

Albania

Albania's population in 1989 recorded 3,182,417 people, the largest for any census. Since then, its population declined to an estimated 2,893,005 in January 2015. The decline has since accelerated with a 1.3% drop in population reported in 2021 leaving a total population of 2.79 million. This represents a decrease of 12% in total population since the peak census figure.

Bosnia and Herzegovina

Bosnia and Herzegovina's population peaked at 4,377,033 in the 1991 Census, shortly before the Yugoslav wars that produced tens of thousands of civilian victims and refugees. The latest census of 2016 reported a population of 3,511,372. This represents a 19.8% decline since the peak census figure.

Bulgaria

Bulgaria's population declined from a peak of 9,009,018 in 1989 and since 2001, has lost yet another 600,000 people, according to 2011 census preliminary figures to no more than 7.3 million, further down to 7,245,000. This represents a 24.3% decrease in total population since the peak and a −0.82% annual rate in the last 10 years.

The Bulgarian population has fallen by more than 844,000 people, or 11.5 percent, in the last decade, the National Institute of Statistics in Sofia said during a presentation of the results so far of the 2021 census, the first since 2011.

The country currently employs just over 6.5 million people, compared to 7.3 million in the previous workforce.

Croatia

Croatia's population declined from 4,784,265 in 1991 to 4,456,096 (by the old statistical method) of which 4,284,889 are permanent residents (by the new statistical method), in 2011, a decline of 8% (11.5% by the new definition of permanent residency in 2011 census). The main reasons for the decline since 1991 are: low birth rates, emigration and war in Croatia. From 2001 and 2011 main reason for the drop in population is due to a difference in the definition of permanent residency used in censuses till 2001 (censuses of 1948, 1953, 1961, 1971, 1981, 1991 and 2001) and the one used in 2011.Croatian Bureau of Statistic
Notes on methodology (Census 2011)
, retrieved 7 July 2013 By 2021 the population dropped to 3,888,529, a 9.25% decrease from 2011 numbers.

Greece

Greece's population declined by about half a million people between its 2011 and 2021 censuses. The main drivers are increased emigration rates and lower birth rates following the 2008 financial crisis.

Romania

Romania's 1991 census showed 23,185,084 people, and the October 2011 census recorded 20,121,641 people, while the state statistical estimate for 2014 is 19,947,311. This represents a decrease of 16.2% since the historical peak in 1991.

Serbia

Serbia recorded a peak census population of 7,822,795 in 1991 in the Yugoslav era, falling to 7,186,862 in the 2011 census. That represents a decline of 5.1% since its peak census figure.

Other

Italy

Although Italy had recorded more deaths than births continuously since 1993, the country's population only peaked in 2015 at 60,796,000 due to substantial immigration. The Italian population fell by a record amount in 2020, and in 2021, it recorded the lowest number of births since its unification in 1861 at only 399,431, with its population being projected to shrink to 47.2 million in 2070, a decline of nearly 20 percent.

As of April 2024, Italian population stands at 58,968,501 inhabitants. The UN's Population Division, assuming that Italy's total fertility rate will rise from 1.2 in 2024 to 1.5 by 2100, projects its population to be 35.5 million by 2100, a decline of about 40%.

Uruguay

Uruguay's fertility rate had been consistently low in Latin America since the 20th century at 3 children per women, with the fertility rates in Latin American countries converging at 2 children beginning in the 1990s, but Uruguay's fertility rate declined sharply from 2 in 2015 to 1.28 in 2022, largely due to decreased births to women under 20. Uruguay recorded more deaths than births for the first time in 2021 and the population decline has been only offset slightly by immigration.

Venezuela

In spite of a positive natural increase of almost 1% per year, Venezuela's population has declined during the 2015-20 period due to emigration caused by threats of violence as well as shortages of basic needs.

Resumed declines

Russia

The decline in Russia's total population is among the largest in numbers, but not in percentage. After having peaked at 148,689,000 in 1991, the population then decreased, falling to 142,737,196 by 2008. This represents a 4.0% decrease in total population since the peak census figure. However, the Russian population then rose to 146,870,000 in 2018. This recent trend can be attributed to a lower death rate, higher birth rate, the annexation of Crimea and continued immigration, mostly from Ukraine and Armenia. It is some 40% above the 1950 population.

Russia has become increasingly reliant on immigration to maintain its population; 2021 had the highest net immigration since 1994, despite which there was a small overall decline from 146.1 million to 145.4 million in 2021, the largest decline in over a decade. The natural death rate in January 2020, 2021, and 2022 have each been nearly double the natural birth rate.

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