Demographics Expert Answers Population Questions | Tech Support | WIRED

World Population and Demographics

• Approximately 108 billion people are estimated to have ever lived on Earth, with 8 billion currently living, making up about 7% of the total number of people who have ever taken a breath on the planet (18s).
• The majority of the world's population is adults, with 70% being over the age of 18, even in Africa, which is the youngest region in the world, where 54% of the population is adults (40s).
• The world population is growing older due to a decrease in the number of children per woman, with the average woman globally having two children in her lifetime, down from four about 50 years ago (1m7s).
• The center of gravity of the world's population has shifted over time as the average number of children per woman has decreased (1m17s).

US Demographics and Immigration

• Asian-Americans are the fastest-growing minority in the United States, making up about 7% of the US population (1m37s).
• Red states tend to be more rural, have an older population, and are whiter, while blue states have more urban areas, are ethnically or racially diverse, and have a younger population, although these patterns do not always hold true (1m54s).
• Immigration contributes significantly to the growth of the working-age population in the United States, with immigrants being most likely to be of working ages, and the US having a total fertility rate below replacement level (3m1s).
• If the US were to stop all immigration, the population would shrink by over 30% by the end of the century (3m30s).

Fertility Rates and Population Pyramids

• Fertility rates matter because they impact a country's age structure and size, with low fertility rates affecting the population's growth and demographics (3m39s).
• A population pyramid with a classic shape, such as Ethiopia's, indicates a population with high fertility rates, where women have more than two children on average, resulting in a larger proportion of younger people in the country (3m54s).
• In contrast, a country like Turkey has a population pyramid with a center of gravity in the middle, indicating close to replacement level fertility rates, with an average of 1.9 children per woman, resulting in an aging population (4m15s).
• Japan's population pyramid is more like a tree, with a large proportion of older people, due to low fertility rates and increased longevity, resulting in a narrowing at the bottom of the pyramid (4m35s).
• Fertility rates matter for policymakers, as they affect the need for schools, jobs, and planning for retirement ages, with countries like Ethiopia needing to build schools and create jobs, while countries like Turkey need to plan for retirement, and countries like Japan need to support a growing population of older people (4m51s).

Global Population Growth and Decline

• The world population is not expected to reach 50 billion, with estimates suggesting it will peak at around 9-10 billion people by 2080, due to declining fertility rates and predictable trends in mortality rates (5m51s).
• The uncertainty in population projections comes from the rate at which fertility rates will fall in places where they are currently high, such as sub-Saharan Africa, where there are only eight countries with fertility rates of five or more children per woman (6m7s).
• Despite Elon Musk's concerns about population decline, global population growth has been declining since the 1960s, and the rate of growth is expected to continue to decline, with the world population projected to peak at around 9-10 billion people by 2080 (6m59s).
• There are over 60 countries worldwide with shrinking populations, which can be attributed to low birth rates, with some countries like Singapore having an average of one child per two parents, leading to a decline in population over time (7m26s).
• This trend is concerning for governments and individuals like Elon Musk, as it results in smaller generations, fewer producers, and fewer consumers, ultimately affecting economic vitality and national security (7m53s).
• Depopulation is a real issue, with many governments worried about its implications, and it's not limited to small towns, as countries like China, Italy, South Korea, and Japan are experiencing rapid population decline (8m11s).
• The effects of depopulation can be seen in abandoned homes, closed storefronts, and a lack of job opportunities in rural areas, making it difficult for young people to replace the aging population (8m46s).
• While the United States is not shrinking overall, there are places within the country that are experiencing depopulation, and retirees are sometimes moving to rural areas, but not for job opportunities (9m24s).
• The United States has seen examples of depopulation in the past, such as Detroit, but the current scale is unprecedented, and once an area starts to depopulate, it can accelerate the process (9m31s).

Immigration Patterns and US Population Changes

• The top countries of origin for US immigrants in 2022 were Mexico, India, China, the Philippines, and El Salvador, with Latin America accounting for 50% of immigrants, followed by Asia at 31% (10m1s).
• Immigration patterns are changing over time, with Mexico's economy growing and its total fertility rate decreasing, resulting in less Mexican immigration to the US, while countries to the south of Mexico are experiencing increased instability, driving northward migration (10m21s).
• The US population has undergone significant changes between the 2010 and 2020 censuses, with growth in places like California and decline in the Northeast, particularly due to people moving to states without income taxes like Tennessee, Florida, and Nashville (11m13s).
• The US Southeast experienced growth of about 1.1% between mid-2022 and mid-2023, while the Northeast shrank, and other regions had minimal growth or decline (11m50s).

Population Density and Growth Factors

• Manila, Philippines, is the most densely populated city in the world, with approximately 46,000 people per square kilometer (12m12s).
• The world population increased drastically after 1900 due to improvements in public health, sanitation, nutrition, and antibiotics, allowing people to live into their reproductive ages (12m23s).
• The global population grew slowly until around 1800, when it reached 1 billion people, and then accelerated to reach 8 billion people, with significant increases in life expectancy (12m58s).

Generational Differences and Family Structures

• Maine has the oldest population in the US, with 23% of the population above age 65, while Utah has the youngest population, with 27% of the population under age 18 (13m18s).
• Utah's young population is partly due to its sizable Mormon population, which tends to have higher birth rates than other US populations (13m34s).
• The biggest difference between Millennials and Gen Z is that Gen Z is larger globally, but Millennials are larger in the US, and Gen Z is more racially diverse, with a higher percentage of multi-racial individuals (13m48s).
• Gen Z in the US also has a higher percentage of Hispanic individuals compared to Millennials (14m17s).
• The "Sandwich Generation" refers to individuals who care for both younger children and older parents, often due to people having children later in life, and can be a challenging situation (14m27s).

Impact of Undocumented Immigrants and Life Expectancy

• If all undocumented immigrants in the United States were deported, certain industries such as agriculture and construction would face labor shortages, leading to increased prices for food and housing, and families with undocumented members would be separated (15m3s).
• Over 16 million people in the United States live in households with at least one undocumented person, and over 7% of all children have at least one undocumented parent (15m33s).
• Factors such as income, race, and geographic location significantly affect life expectancy, with poorer counties in the United States having lower life expectancy rates (15m56s).
• A map of the United States shows that counties with lower median incomes, such as McDowell County in West Virginia and Buffalo County in South Dakota, have lower life expectancy rates (15m58s).
• Life expectancy is also affected by income at a global scale, with high-income countries having an average life expectancy of 81 years, middle-income countries at 73 years, and low-income countries at 65 years (16m48s).
• Females tend to live longer than males globally, with an average life expectancy of 76 years compared to 71 years for males (17m0s).
• Men tend to be in riskier jobs and have higher mortality rates at older ages, resulting in women outliving men (17m10s).
• The country with the lowest life expectancy at birth for males is Chad at 53 years, and for females is Nigeria at 55 years (17m44s).
• The country with the highest life expectancy at birth for males is Monaco at 84 years, and Japan has one of the highest life expectancies for females at 87 years (17m56s).
• Healthy life expectancy, which measures the number of years lived in good health, is distinct from overall life expectancy, and ideally, the gap between the two should be narrow (18m33s).
• The gap between healthy years lived and overall years lived varies across countries, with Haiti having a gap of 8 years, Japan having a gap of 10 years, and the United States having a gap of 12 years, indicating that Americans live many more years in less than ideal health compared to other countries (18m44s).
• This gap affects how long people can work and how many years they can live healthy after retirement, making it a relevant concern for countries with aging populations (19m10s).

China's One-Child Policy and Sex Ratio Imbalance

• The most populous country on Earth is India, followed by China, both with approximately 1.4 billion people, while the United States, Indonesia, and Pakistan have significantly lower populations (20m9s).
• China's one-child policy, implemented in 1979, led to a skewed sex ratio at birth due to sex-selective abortion, with nearly 160 males born for every 100 females born for third babies, compared to the natural sex ratio of 105 males born for every 100 females (21m48s).
• This policy has resulted in millions more males than females in certain age groups, exacerbating China's already low fertility rates and rapidly shrinking population (22m11s).
• The natural sex ratio at birth is approximately 105 males born for every 100 females, but in China, the preference for male children led to a significant imbalance in the sex ratio at birth (20m51s).
• The one-child policy was particularly restrictive, with most families only allowed to have one child, leading to a strong preference for male children and resulting in sex-selective abortion (20m41s).

US Health and Demographic Concerns

• The United States is an outlier in terms of the gap between healthy years lived and overall years lived, with significant implications for the economy as the population ages (19m28s).
• A significant demographic concern is a youthful population, where a large proportion of the population is of younger ages, such as in Niger or Mali, which can lead to a greater risk of coups and political instability, but also presents opportunities for economic growth (22m40s).

Demography and Population Growth

• Demography is the study of human populations, focusing on changes in fertility, mortality, and migration, which in different combinations give rise to various outcomes (23m12s).
• The two fastest-growing countries are South Sudan and Chad, with populations growing at about 6% per year, primarily due to high fertility rates in Sub-Saharan Africa (23m36s).
• Sub-Saharan Africa has the highest fertility rates globally, and by 2050, one out of every four children in the world will be African, while Northern Africa has lower fertility rates (23m45s).
• A population grows when there are many people of reproductive ages and a high number of births per person, with over half of the world's projected population growth between now and 2050 coming from just eight countries, including India (24m4s).
• India's population is still growing despite having below-replacement fertility rates due to the momentum of past cohorts of women of reproductive ages being larger when fertility rates were higher (24m21s).
• Latin American migrants to the United States tend to have high birth rates due to their age, typically being of working and reproductive ages, but their fertility rates usually decrease to match those of the native-born population within a generation (24m56s).

Population Measurement and Estimation

• The population of the United States is counted through a census every 10 years, as well as regular surveys like the Current Population Survey or the American Community Survey, which provide a snapshot of the population between censuses (26m0s).
• To estimate the number of illegal or irregular immigrants, demographers take the number of legal migrants and subtract it from the total population in an area, using the residual as an estimate, although this method is not always accurate (26m22s).
• Some people may not answer surveys, and households with both legal and illegal immigrants may not accurately report their numbers, making it difficult to track the population (26m45s).
• Demographers use context clues and data to estimate the population, but these estimates are taken with a grain of salt (27m3s).

Urbanization and Mega Cities

• A new study suggests that in the future, most of the world will live in mega cities, which are areas with a population of 10 million or more, although this trend may vary depending on the country (27m10s).
• Currently, over 58% of the world's population lives in urban areas, a significant increase from 3% in 1800, although some people are leaving urban areas for smaller cities or suburban areas (27m47s).

US Mortality Rates and Healthcare Disparities

• Mortality rates in the US compare to other countries by looking at the number of people dying per 1,000, but life expectancy at birth is a more relevant measure, with the US having a life expectancy of 78 years, lower than Canada's 82 years (28m24s).
• The US life expectancy has not kept pace with increases in other countries, due to poor health and uneven access to healthcare, with significant disparities by race and geographic location (28m39s).
• Non-Hispanic black women in the US are 1.5 times more likely to die during pregnancy or shortly after than non-Hispanic white women, contributing to lower life expectancy (28m55s).

Ukraine's Population Decline and Emigration

• Ukraine's population is declining rapidly due to a combination of low fertility rates and mass emigration, with around 10 million people having left the country since the war started (29m23s).
• The country already had a history of people leaving for opportunities in Western Europe, and its fertility rates were well below replacement levels even before the war (29m36s).
• There is little that the government can do to raise fertility rates, as evidenced by the experiences of countries such as Germany, Canada, and Japan, which have tried using tax incentives and other measures to encourage people to have more children (29m57s).
• Once the war ends and the country begins to rebuild, it is hoped that the peace and new economic opportunities will attract some of the emigrants to return and start building their lives in Ukraine again (30m12s).
• The return of some of the 10 million people who left may help to mitigate the population decline, but the situation remains serious and challenging for the country (30m18s).

The Power of Demography

• Demography provides a powerful lens through which to view the complex world of 8 billion people and understand the population trends and challenges facing countries like Ukraine (30m25s).