Skip to main content

Main Area


Can you name the 50 biggest countries in the world?

Mazur Travel // Shutterstock

Can you name the 50 biggest countries in the world?

The story of a country's population growth often can be traced to larger societal factors in each country. For example, economic and social development often brings with it a decline in birth rates, for a number of reasons. For example, expanding access to education for women and girls often means that women delay childbirth to complete their educations and enter the workforce; if and when they have children, they end up having fewer. Changing social mores around family planning and birth control can accompany periods of development and result in families having far fewer children, as women take their reproductive health into their own hands.

Health care is another broader social factor that plays a significant role in population growth. When health care in a country improves, its citizens are likely to live longer, pushing down the death rate. Improvements in health services also affect infant and maternal mortality rates, improving the odds that both mother and baby will survive childbirth.

Although it may seem as though it is purely an asset to have a large population, countries whose economies can't keep up with their population growth face real problems. Joblessness can lead hopeless young people into criminality and even terrorism. A population without resources to care for itself and without a robust social safety net likely will be beset by rising death rates, violence, and poverty.

A large population also can be a tremendous benefit to a country economically and developmentally. A broader labor base allows for increased productivity and output, and creates a demand for health, education, and other social services.

Stacker took a look at the 50 most populous countries in the world, based on data from the United Nations, along with the social factors that may be influencing their broader demographic trends. Click through to see how the world's largest countries are handling their large numbers of citizens, and whether their populations are on track to expand or contract.

You may also like:Tourism industry by the numbers


#50. Nepal

- 2018 population: 28.1 million
- 1950 population: 8.5 million
- 1950-2018 population growth: 231.2%

A small, landlocked country between China and India, Nepal is home to the greatest altitude variation in the world, from low-lying plains to the soaring peaks of Mount Everest. It's also seen a huge population boom starting in the second half of the 20th century, though it's slowed in recent years. Rapid population growth has caused deforestation that increases flooding in the plains regions and a large percentage of Nepalese citizens living in poverty, so many have migrated out of the country in search of better opportunities.

Rod Waddington // Flickr

#49. Yemen

- 2018 population: 28.5 million
- 1950 population: 4.7 million
- 1950-2018 population growth: 511.4%

Booming birthrates have left Yemen with an extremely young population; the median age in the country is just 19. The economy has struggled to keep up with the fast-paced growth, leaving many Yemeni young people unemployed and struggling. Additionally, Yemen's population has recently been devastated by both famine and a brutal civil war that has displaced millions and left as many as half of its citizens in need of urgent humanitarian aid, according to U.N.'s Office for the Coordination of Humanitarian Affairs

Wilfredor // Wikimedia Commons

#48. Venezuela

- 2018 population: 28.9 million
- 1950 population: 5.5 million
- 1950-2018 population growth: 426.9%

Venezuela is currently facing a migration crisis, with 7% of the country's total population (or about 4 million people) having fled across since 2014, according to a joint statement by the U.N. refugee agency (UNHCR) and International Organization for Migration. An economic crisis has ravaged the country, causing hyperinflation that makes it difficult to buy necessities like food and medicine, while at the same time Venezuela's President Nicolás Maduro has become increasingly authoritarian. The Organization of American States has warned that the mass exodus from Venezuela could become the largest in the world as early as 2020.

nooaonphoto // Shutterstock

#47. Mozambique

- 2018 population: 29.5 million
- 1950 population: 6 million
- 1950-2018 population growth: 395%

The civil war that ravaged Mozambique in the 1980s and early 1990s officially ended in 1992 and the country has been at peace since then, allowing millions of displaced people to return to their country with the help of the United Nations. High birth rates (the average woman in Mozambique has four to five children) have allowed the population to continue growing at a steady clip.


#46. Ghana

- 2018 population: 29.8 million
- 1950 population: 5 million
- 1950-2018 population growth: 491.1%

Ghana, like many other developing countries, has a high birth rate, averaging four children per woman, and a young population, with around 57% of its population under 25, according to the Central Intelligence Agency. But unlike some other countries, Ghana has been able to halve its poverty rate and maintain a relatively stable economy, despite losing skilled doctors and other workers to the United States. Officials hope to get an even more accurate count of the country's population in 2020 with a new digital census to better identify areas of concentrated high poverty and root out inequality.

Fabian Plock // Shutterstock

#45. Angola

- 2018 population: 30.8 million
- 1950 population: 4.5 million
- 1950-2018 population growth: 577.4%

One of the least densely populated countries in Africa, Angola is also one of the fastest-growing on the continent, despite an economic slowdown following a fall in oil prices. The CIA reports that almost half its population is under the age of 15 and the country's fertility rate shows no signs of slowing down, in addition to thousands returning home after the end of the country's civil war in 2002.

r.nagy // Shutterstock

#44. Malaysia

- 2018 population: 31.5 million
- 1950 population: 6.1 million
- 1950-2018 population growth: 416%

Although Malaysia's population is growing, the demographics of its population growth points toward several important trends. The population below the age of 14 actually fell in an atmosphere of overall growth, suggesting declining birth rates, reports the Department of Statistics Malaysia. Death rates are also on the decline, which may be because of improved medical care in rural areas.


#43. Peru

- 2018 population: 32 million
- 1950 population: 7.8 million
- 1950-2018 population growth: 311.3%

In the past decade, serious market-oriented reforms have contributed to Peru's growth as one of the best-performing economies in Latin America, with unemployment and poverty levels falling dramatically. Along with this rising tide of fortune for ordinary Peruvians has come a shift in population demographics, with many more Peruvians leaving remote areas in the jungle for opportunities in the country's cities, and an influx of people fleeing into Peru as a safe harbor from neighboring Venezuela, which is being rocked by economic and political crises.

MehmetO // Shutterstock

#42. Uzbekistan

- 2018 population: 32.5 million
- 1950 population: 6.3 million
- 1950-2018 population growth: 418.5%

Since Uzbekistan became an independent country after the dissolution of the USSR in 1991, its economy has diversified and developed tremendously, leveraging its rich store of agriculture, minerals, and petroleum. Although the country is generally sparsely populated, its population concentrations in places like the Fergana Valley are among the highest in the world, according to the CIA. A key factor slowing down Uzbekistan's population growth since 1991 is the declining birth rate. In the Soviet era, subsidies were provided for each additional child; some families had as many as eight or nine children.

Fitria Ramli // Shutterstock

#41. Saudi Arabia

- 2018 population: 33.7 million
- 1950 population: 3.1 million
- 1950-2018 population growth: 979.9%

Despite its famously repressive rulers, Saudi Arabia's population growth can in some measure be attributed to the country's status as one of the world's largest labor markets. In 2017, the General Authority for Statistics reported that a whopping 37.3% of the country's population were non-Saudi expatriates, who primarily work in the industrial and service sectors.


#40. Morocco

- 2018 population: 36 million
- 1950 population: 9 million
- 1950-2018 population growth: 300.9%

Morocco is in the midst of a serious demographic shift, along with its recent political and economic reforms. The country's population is still increasing, but the rate of growth is slowing as birth rates decline and life expectancy increases. Developments in education and health care can largely account for both trends, with improvements in hygiene, vaccinations, and nutrition resulting in longer life spans, and contraceptive use and female education contributing to declining birth rates.


#39. Canada

- 2018 population: 37.1 million
- 1950 population: 13.7 million
- 1950-2018 population growth: 170%

Among the main drivers of Canada's population growth are events that take place far from Canadian borders. With turmoil and violence engulfing many parts of the Middle East and Africa since 2011, Canada's welcoming asylum and refugee policies have played a significant role in the country's population growth. In 2018 alone, a Statistics Canada report showed that immigrants made up a notable 61% of the country's population growth—attributable also, perhaps, to the country's generous social benefits.


#38. Afghanistan

- 2018 population: 37.2 million
- 1950 population: 7.8 million
- 1950-2018 population growth: 379.5%

Afghanistan's recent history is marred by violence and chaos. The U.S. invasion in 2001 was meant to usher in democracy, but democracy in the country is tenuous, and the Taliban remains a potent force, considering itself the legitimate government. The country's dynamic population growth, due in part to low rates of family planning, will cause serious challenges, as population growth has not been matched by economic growth to support it, says the Central Statistics Organization. 

TTstudio // Shutterstock

#37. Poland

- 2018 population: 37.9 million
- 1950 population: 24.8 million
- 1950-2018 population growth: 52.8%

Since the end of the Soviet era, an independent Poland has moved decisively toward its current status as a Western, democratic, market-oriented country. However, Poland's long-term economic success came at a cost to its population. In the immediate post-Soviet environment, economic levers pulled by the government caused wages to drop by 40%, leading many Poles to leave the country for better-paying opportunities elsewhere. Poland joining the European Union in 2004 only exacerbated the problem.


#36. Iraq

- 2018 population: 38.4 million
- 1950 population: 5.7 million
- 1950-2018 population growth: 572%

Iraq's recent political history includes an invasion by the United States, the overthrow of its leader, Saddam Hussein, the shaky installation of a Western-backed government, and a battle against the Islamic States of Iraq and Syria, a terrorist group that controlled significant portions of its territory for several years. Population growth in the midst of this instability is raising concerns, as the country's economic institutions have been largely shattered, and the majority of Iraqis do not benefit from the country's oil reserves. Some estimates place Iraq's population growth at 1 million people per year.

Sergey-73 // Shutterstock

#35. Sudan

- 2018 population: 41.8 million
- 1950 population: 5.7 million
- 1950-2018 population growth: 629%

Sudan's relatively short history as an independent country has been rife with conflict, including multiple civil wars that resulted in the independence of South Sudan in 2011. Population demographics are skewed, with over 60% of the population under the age of 24, and only 3% percent of the country over the age of 65, illustrating the country's low average life expectancy. One of the most interesting facets of Sudan's demographic is the preponderance of the population that is female, which may be attributable to men leaving the country to seek work elsewhere.


#34. Algeria

- 2018 population: 42.2 million
- 1950 population: 8.9 million
- 1950-2018 population growth: 376%

Before 2000, population growth in Algeria had slowed along with its neighbors in north Africa, as women began attaining higher education in greater numbers and having fewer children later in life. But Algeria's population has exploded, reaching 1 million births per year in 2014, and is still climbing. Algeria's health ministry has launched a family planning campaign to slow down the birth rate, as not to overtax the country's social services programs.

Pecold // Shutterstock

#33. Uganda

- 2018 population: 42.7 million
- 1950 population: 5.2 million
- 1950-2018 population growth: 728.4%

In the years immediately following its independence from Britain in the 1960s, Uganda was beset by dictatorship and political violence that killed hundreds of thousands of civilians. The current president has been in power since 1986, and has presided over a period of relative stability. However, positive trends are challenged by the country's exploding population growth, which Population Reference Bureau experts estimate is on track to be the world's highest in the coming years. Poor education around family planning is the primary culprit for Uganda's baby boom, which many fear will be unsustainable, leading to a massive draw on scarce resources.


#32. Ukraine

- 2018 population: 44.2 million
- 1950 population: 37.3 million
- 1950-2018 population growth: 18.6%

Despite still being one of the world's biggest countries, Ukraine's population has been declining slowly for years. Several factors contribute to this—the country has been beset by corruption and political infighting since it became independent with the dissolution of the USSR in 1991. Another factor is the low life expectancy, driven by unhealthy lifestyles—Ukrainian men in particular are big smokers and drinkers. Migration and low birth rates add to the overall decline.


#31. Argentina

- 2018 population: 44.4 million
- 1950 population: 17 million
- 1950-2018 population growth: 160.4%

Competing demographic trends have resulted in relatively slow population growth for Argentina, which is one of the most stable and prosperous countries in South America. Immigration from countries with less stable economies and political climates is driving population up, with as much as 5% of Argentina's population coming from migration. But birth rates have been steadily declining for years, largely offsetting many of the population gains from immigration and longer life expectancy.

May_Lana // Shutterstock

#30. Spain

- 2018 population: 46.7 million
- 1950 population: 28.1 million
- 1950-2018 population growth: 66.3%

Populous Spain has emerged as a prosperous and peaceful western European nation since the end of dictator Francisco Franco's dictatorship in 1975. Two trends typically at odds are contributing to the low population growth rates, however. In 2018, Spain's National Statistics Institute reported the country recorded the lowest number of births and the highest number of deaths since such data began being tracked in 1941. The low birth rate can be attributed in part to Spain's economic crisis, during which fewer couples decided to have children.


#29. Colombia

- 2018 population: 49.7 million
- 1950 population: 12 million
- 1950-2018 population growth: 314.5%

Colombia's changes since the mid-20th century are dramatic and have contributed to the country's declining population growth. Fertility rates have dropped from six children per household in the 1960s to just above replacement level today, thanks to increases in family planning. Significant political violence and loss of economic opportunity also have caused a significant number of Colombians to migrate abroad and made the country a less attractive place for immigrants to settle.

CJ Nattanai // Shutterstock

#28. South Korea

- 2018 population: 51.2 million
- 1950 population: 19.2 million
- 1950-2018 population growth: 166.4%

Visitors to the bustling capital city of Seoul may find it difficult to believe, but South Korea's population has actually been steadily declining for years. The country's health ministry warned that the country is at risk of sliding backwards to 1972 population levels by 2067 unless current trends are reversed. Experts largely attribute Korea's very low fertility rate to the high cost of child rearing in Korea, with education and even marriage seeming out of reach for many couples.


#27. Kenya

- 2018 population: 51.4 million
- 1950 population: 6.1 million
- 1950-2018 population growth: 745.7%

Kenya's population has grown at an astonishing rate over the past several decades throughout the country's transition to democracy and despite significant post-electoral violence that rocked the country in 2008. However, the drivers of population growth have changed considerably. Until around 2000, Kenya's population growth was due to increasing birthrates. Although birthrates have slowed, the high levels of fertility in the past led to a large number of families today able to have children of their own. In the post-2000 era, higher life expectancy has led to many Kenyans aging well past their predecessors, welcoming grandchildren and great-grandchildren.


#26. Myanmar

- 2018 population: 53.7 million
- 1950 population: 17.8 million
- 1950-2018 population growth: 202.1%

Myanmar's rocky transition from military dictatorship to democracy and its government's suppression of Rohingyas—an ethnic minority—have contributed to its declining population growth. The violence against the Rohingyas has caused an outflow of 710,000 of the Muslim minority group to flee to neighboring Bangladesh. However, decreasing infant mortality rates and improvements in life expectancy have countered the decline to some degree.

E X P L O R E R // Shutterstock

#25. Tanzania

- 2018 population: 56.3 million
- 1950 population: 7.7 million
- 1950-2018 population growth: 636.1%

Tanzania's rapid population growth is raising alarm among world's leaders, with the United Nations Population Fund stating that the high growth rate challenged the agency's poverty reduction goals. The high birth rate is particularly cyclical and vexing, as it creates a larger population for development agencies to spend the same amount of resources on, including agencies that focus on family planning.


#24. South Africa

- 2018 population: 57.8 million
- 1950 population: 13.6 million
- 1950-2018 population growth: 324.1%

South Africa's economy may be booming, but its population is growing even faster, and that's a problem, many population experts say. Lower infant mortality rates, increased life expectancy, and a significant decrease in the number of AIDS-related deaths have all contributed to a swell in the country's population. And while the economy is growing, it will need to grow at an even higher rate to keep the increasing population employed and out of poverty.


#23. Italy

- 2018 population: 60.6 million
- 1950 population: 46.6 million
- 1950-2018 population growth: 30.1%

The economic crises that rocked the globe in 2008 hit Italy particularly hard, with fears of a “perma-recession” lingering more than a decade later. The falling economic fortunes of the country's citizens has led to a steady decline in birth rates, with many families stating that they wish to have children, but cannot afford it. Higher life expectancy has led to a “graying” of Italy's population, and has sparked fears that fewer births will mean even fewer resources with which to care for the aging population.


#22. France

- 2018 population: 65 million
- 1950 population: 41.8 million
- 1950-2018 population growth: 55.4%

In 2017, the prosperous Western nation of France hit an all-time population high of 66.9 million. One of the most significant drivers of growth is the country's high rate of immigration, with net migration per year of 70,000. France also has one of the highest birth rates in Europe, and the highest life expectancy it has ever experienced.


#21. United Kingdom

- 2018 population: 67.1 million
- 1950 population: 50.6 million
- 1950-2018 population growth: 32.6%

Great Britain's 2016 vote to exit from the European Union—the details of which are still being worked out—may have been intended to keep the country independent from the rest of the world, but the rest of the world doesn't seem to be listening. The Office for National Statistics reports the migrant population actually increased in the year after the “Brexit” referendum, offsetting declining birth rates and higher death rates to still provide the country with modest population growth.

SOUTHERNTraveler // Shutterstock

#20. Thailand Office for National Statistics

- 2018 population: 69.4 million
- 1950 population: 20.7 million
- 1950-2018 population growth: 235.2%

The past several years have made an economic case study out of Thailand, with rapid rates of economic growth pushing many more of the country's citizens into the middle class. However, economic expansion may have come at a population cost. Thailand's population has almost stopped growing, as many Thai citizens are focused on economic opportunity over childbearing. Increased education rates have resulted in many women delaying having children, driving down the number of births over the long term.

Mazur Travel // Shutterstock

#19. Iran

- 2018 population: 81.8 million
- 1950 population: 17.1 million
- 1950-2018 population growth: 377.8%

Iran is frequently in the news, thanks to its persistent friction with the United States, which recently pulled out of a major nuclear accord struck with Iran in 2015. Despite its presence on the world stage, Iran's birth rate is falling. The decline is largely attributable to the declining fertility rate, and Iran's leaders have stressed that they are trying to put in place economic and social infrastructure to support families having more children.


#18. Turkey

- 2018 population: 82.3 million
- 1950 population: 21.4 million
- 1950-2018 population growth: 284.6%

Turkey's current leader may have survived a coup attempt and presided over a restriction of democratic freedoms, but population growth doesn't seem to be far from top of mind, either. As Turkey's fertility rates decline, President Recep Tayyip Erdogan has encouraged women to have three children each. He may be facing strong social headwinds. “People in the upper social groups in Turkey have one or two children, they don't have three or four,” one doctor told The Guardian. “People with larger families are in lower socio-economic groups.”


#17. Germany

- 2018 population: 83.1 million
- 1950 population: 70 million
- 1950-2018 population growth: 18.8%

Germany may be known as the “economic engine” of Europe, but its low rate of population growth is causing headaches for the country's leaders. Germany has one of the oldest populations in Europe, and one of the lowest fertility rates, with projections by the U.N. to lose a net of 10 million people by the end of the century. The massive influx of migrants from around the world may help offset the trend, suggest officials from the Federal Statistics Office. 

Valeriya Anufriyeva // Shutterstock

#16. Democratic Republic of the Congo

- 2018 population: 84.1 million
- 1950 population: 12.2 million
- 1950-2018 population growth: 590%

The Democratic Republic of Congo has been beset by poverty and violence since its independence from Belgium in 1960. The country is one of the poorest in the world. Low life expectancy and high infant and maternal mortality rates are no match for the high fertility rate, which is largely due to scant family planning, and a cultural preference for larger families. The high rate of population growth risks overtaxing an already strained society.


#15. Vietnam

- 2018 population: 95.5 million
- 1950 population: 24.8 million
- 1950-2018 population growth: 285.1%

After North Vietnam and South Vietnam reunited into one country in the 1970s, the country's growth rate took off, with 1 million net people being added to the country each year. Despite this rate, actual population growth slowed significantly, thanks largely to the country's declining birth rate. The government's institution of a “two child” policy has dropped the birth rate from five children per family in 1980 to two in 2017, according to Euromonitor International. 


#14. Egypt

- 2018 population: 98.4 million
- 1950 population: 20.5 million
- 1950-2018 population growth: 381.2%

Egypt has gone through three different governments since 2011 alone, but the country's political instability isn't doing much to hamper its population growth. Egypt has been unable to stem fertility rates as effectively as other countries, straining an already overtaxed education and social welfare system, and foreshadowing looming employment crises, which may lead to more political discontent and instability.


#13. Philippines

- 2018 population: 106.7 million
- 1950 population: 18.6 million
- 1950-2018 population growth: 474%

Although the Philippines remains a highly populous developing nation, it faces real demographic challenges. Because of the country's development, fertility rates are declining as contraceptives become more widely used, while its number of senior citizens has increased as life expectancy goes up. This common trend in the developing world has experts concerned about how to create jobs and economic opportunities so the smaller share of a younger population has the resources to support the aging population.


#12. Ethiopia

- 2018 population: 109.2 million
- 1950 population: 18.1 million
- 1950-2018 population growth: 502.5%

Ethiopia's large population has come at a cost to the country, with significant amounts of over-farming and deforestation inhibiting its ability to develop economically, and at a significant cost to its environment. The stress a high rate of population growth puts on the country's resources only furthers these downward trends, and Ethiopia has experienced significant droughts, famine, and food insecurity in recent years as a result.


#11. Mexico

- 2018 population: 126.2 million
- 1950 population: 27.9 million
- 1950-2018 population growth: 351.6%

Although many countries in the developing world are struggling with declining fertility rates, higher life expectancies, and the ensuing “graying” of their countries, Mexico faces one of the starkest challenges. Mexico's current economic structure does not provide robust benefits for retirees, and many Mexicans continue working into old age.


#10. Japan

- 2018 population: 127.2 million
- 1950 population: 82.8 million
- 1950-2018 population growth: 53.6%

Japan is one of the world's most populous countries, but the rate of its population decline has been rapid, and is only growing faster. Demographics specific to Japan are contributing to the decline, particularly the high death rate. Ramping up for World War II, Japan's government pushed its citizens to have lots of children, and those born during the baby boom around that time are now passing away, contributing to the steep decline.


#9. Russian Federation

- 2018 population: 145.7 million
- 1950 population: 102.8 million
- 1950-2018 population growth: 41.8%

Russia is home to some 146 million people—fewer, if you don't consider people living in regions seized by Russia in 2014, including Crimea—but the country's population growth rate has recently begun to decline because of mortality rates. Experts point to a hard-drinking culture for Russian men, in particular. One report prepared for a government council on social policy showed that Russian men in prison lived longer than those outside of prison, and suggested alcohol was the reason.


#8. Bangladesh

- 2018 population: 161.4 million
- 1950 population: 37.9 million
- 1950-2018 population growth: 325.9%

Once one of neighboring Pakistan's poorest regions, Bangladesh remained mired in poverty for years after its independence in 1971. But a spate of social reforms, particularly those empowering women and encouraging them to participate in the economic life of the country, have powered significant economic growth. The persistently high birth rate troubles some experts, along with the high adolescent birth rate, and efforts to encourage family planning have stubbornly resisted change.

ariyo olasunkanmi // Shutterstock

#7. Nigeria

- 2018 population: 195.9 million
- 1950 population: 37.9 million
- 1950-2018 population growth: 417.4%

Oil-rich Nigeria is sub-Saharan Africa's largest economy, and in the 21st century has emerged as a true, if new, democracy. Nigeria also has the largest population in Africa, and its growth rate shows no signs of slowing. Early marriages, high birth rates, and little access or appetite for family planning have all contributed to Nigeria's explosive growth, and threaten the ability of its rising economic tide to lift all boats.


#6. Brazil

- 2018 population: 209.5 million
- 1950 population: 54 million
- 1950-2018 population growth: 288.1%

Brazil's transition from military dictatorship to civilian rule came relatively late in 1985, but since then, the South American nation has been largely peaceful and prosperous, with several economic speed bumps in between. Population growth is on the decline because of fertility rates that have been plummeting since the 1960s, a high life expectancy, and net emigration, thanks to the country's recent economic woes.

Patrick Poendl // Shutterstock

#5. Pakistan

- 2018 population: 212.2 million
- 1950 population: 37.5 million
- 1950-2018 population growth: 465.3%

One of the world's most populous countries, Pakistan makes headlines for its skirmishes with long-running rival India—of which it was formerly a part—and its nuclear weapons testing. A 2017 census showed that the country's population had skyrocketed since the previous census in 1998. The culprit behind the soaring population is a lack of family planning, particularly in rural areas. Experts fear that as Pakistan's many children born each year grow up, there won't be enough jobs for all of them, and that they will be attracted to another of Pakistan's primary issues—homegrown terrorism.

AsiaTravel // Shutterstock

#4. Indonesia

- 2018 population: 267.7 million
- 1950 population: 69.5 million
- 1950-2018 population growth: 284.9%

The world's largest Muslim-majority state, according to the CIA, Indonesia is in a period of transition from decades of authoritarianism into a democracy. Although population growth is expected to continue on an upward trajectory, the country's planning ministry has said that reducing infant and maternal mortality rates is a goal for the country to keep population growth strong.

Songquan Deng // Shutterstock

#3. United States of America

- 2018 population: 327.1 million
- 1950 population: 158.8 million
- 1950-2018 population growth: 106%

The world's oldest constitutional democracy, the United States is arguably the world's predominant superpower, a position it has enjoyed relatively unchallenged since the end of World War II. The country's population growth is in a period of stagnation, with falling birth rates and rising death rates recorded in a recent U.S. census. Some experts attribute declining birth rates to the Great Recession, which has hampered some young adults' economic prospects so severely that they are postponing having children.

sladkozaponi // Shutterstock

#2. India

- 2018 population: 1.35 billion
- 1950 population: 376.3 million
- 1950-2018 population growth: 259.4%

The U.N. projects that India's population will grow to be the largest in the world by 2027, a worrying prospect for a developing country that's already taken steps to reduce the fertility rate at a time when most countries are trying to boost them. A population that continues to grow threatens efforts by the Indian government to curb poverty, end hunger, and improve education systems and economies, as more people put more strain on all these systems.

testing // Shutterstock

#1. China

- 2018 population: 1.43 billion
- 1950 population: 554.4 million
- 1950-2018 population growth: 157.5%

China's “one-child policy,” which required Chinese families to limit themselves to one child in order to keep the population from hindering economic growth, was repealed and replaced with a two-child policy in 2015, but its effects are still being felt in the world's largest country. The one-child policy caused a huge gender imbalance of about 30 million more men because of a cultural preference for male children, leaving China with an older population less likely to have another child. The birth ratio is still one of the most gender imbalanced in the world and, as China's population ages, there are worries there won't be enough young workers to maintain current economic strength. China's overall population is projected to shrink by millions in the coming decades.

2018 All rights reserved.