Demographics Expert Answers Population Questions

I'm Jennifer Sciubba, and I study demographic data.

Let's answer your questions from the internet.

This is Population Support.

[upbeat music]

@Virilian4: How many people have ever lived

on this earth?

So there have been about 108 billion people, as an estimate,

who have ever taken a breath on planet Earth.

If you went back to say, year one,

there would be about 55 billion people

who had ever taken a breath.

And there are 8 billion people who live on planet Earth,

7% of the 108 billion who have ever taken a breath.

Here's a question from Quora.

Is the majority of the world's population

children or adults?

Well, the majority of the world's population is adults.

70% of us are over the age of 18.

Even in Africa, which is the youngest region in the world,

54% of the population is adults.

Countries have seen a steady increase

in their life expectancy over time.

World population is growing older,

and that's because the number

of children per woman has gone down.

One way to think about it is,

the average woman about 50 years ago

would have had four children in her lifetime,

but the average woman globally today has only two.

So if we think about lining everyone on the planet up

from the youngest person to the oldest person,

like where would the center of gravity be?

The center of gravity has shifted over time

as the average number of children per woman has gone down.

@JDCrowe13: Quiz:

What is the fastest growing minority in America?

If you answered hipster, then you win the prize.

Actually, if you answered Asian Americans,

you would win the prize.

They are the fastest growing minority in the United States,

and they're about 7% of the US population.

@BenPo234: What are the signature demographics

of a red state versus a blue state?

If we think most generally,

a red state most often would be more rural,

probably have an older population, and is whiter.

Blue state would have more urban areas,

ethnically or racially diverse,

and probably a younger population.

But you may notice that it doesn't always map that way.

That's why on election night it wasn't really just enough

for us to see the 50 states projected on the screen

and try to figure out how the election would turn.

You could start to zoom in

and see really different dynamics,

like Tennessee, for example,

that is relatively a red state across,

and then with these little blue dots

in the Memphis, Nashville areas.

A state like Maine is the most rural state

in the United States, but it still has lots of blue areas,

and those are its urban areas.

So if you're talking about like a House race

or a Senate race, you can see how those sub-state red

and blue areas really show up and matter

for what a vote looks like.

@StallmansBeard: Is immigration a net positive

or negative?

One way we wanna think about it is through an economic lens.

In the United States, immigrants are actually most likely

to be of working ages.

The US has a total fertility rate below replacement level

of 1.6 children per woman on average,

means immigration contributes quite a bit

to the growth in the working-age population here.

We can see that foreign-born population,

very few children under five,

very few five to 17 years of age,

much more concentrated in terms of 18 to 64

or those working ages, versus US-born population.

Immigration is kind what propels

that overall population growth.

If the US were to stop all immigration right now,

not do anything else between now and the end of the century,

the US population would shrink by over 30%.

@venompilled wants to know, Why do fertility rates matter?

Well, they matter a lot

because the impact, its age structure for example,

and, of course, its size.

We can actually see this if we look at snapshots in time

of a handful of countries in the world today.

Females on this side and males on this side,

from age zero all the way up to over a hundred.

So if we're looking at Ethiopia here,

we can see this classic pyramid shape means

that it's a population

where women have, on average, more than two children.

So the population is a lot more bottom-heavy,

which means that there are a lot more younger people

in the country there.

If you had one that's fertility rate

of four children per woman on average,

each generation's twice the size of the one before it.

Versus if we look at a country like Turkey,

you can see that that center of gravity in terms of ages

is in the middle more, and that's because they've had close

to replacement level fertility rates for a while,

average number of children of 1.9 per woman.

So we see that that population is growing older.

The bulk of the people would be here of these working ages.

And then we get to Japan.

It's not really a population pyramid anymore,

it's more of a tree.

There are lots of older people in this society.

Some of that is longevity.

And so you can see this narrowing here at the bottom,

and that just shows you that women of reproductive ages,

they're having under replacement level fertility rates.

So why do those fertility rates matter?

If you're in Ethiopia and you're a policymaker,

probably one of your bigger concerns

is how to build enough schools, year after year,

for all of these young people aging into kindergarten,

and then how to have enough jobs for those

who are aging into the workforce.

If you're in Turkey,

you're thinking about the working-age population, certainly,

and their jobs there, but you also need to be thinking

about how, in just a few years, these folks will be moving

into retirement ages, and how do you plan for that?

And if you're in Japan, you're thinking about how schools

are closing year after year.

You have a much smaller workforce needing

to support a growing population of older people.

So age structures, which are affected by fertility rates,

really matter for even setting the agenda

at the national level.

@TommyBoyOH: Is the real issue

that we have too many humans on the planet?

So, in a few hundred years,

when the world population is over 50 billion,

what will our problems be then?

We will never have a population of 50 billion,

at least not anywhere close to it with our trends right now.

Best estimates are somewhere around the year 2080

and we'll top out at between nine and 10 billion people.

Now, we're reasonably certain about this

because our trends in fertility rates and mortality rates,

they're following a fairly predictable pattern.

The uncertainty comes from really just two things.

One is, how fast will fertility rates fall

in places where they're currently still high?

And there really aren't that many places in the world

where fertility rates are really high.

They're mostly concentrated in a few countries

in Sub-Saharan Africa.

We live in a world where there are only eight countries,

out of 200 something countries,

where women have five or more children.

That includes Nigeria, for example,

which is a pretty big country.

Keeps global population young.

We have not seen any indication

that it's gonna come up in places where it's low.

So I feel pretty confident we'll be hitting a peak

of somewhere between nine and 10 billion people

roughly around the year of 2080.

@HawaiianPace asks, How can Elon Musk be worried

about population decline when Nick Cannon exists?

Elon and Nick Cannon maybe have something in common,

which is they might be single-handedly trying

to change global trends.

Global population growth has been declining since the 1960s.

You can see this peak here in the mid 1960s.

So that rate of growth is really going down over time.

This is what's happening beneath the surface,

while on top, we see world population continuing to grow

to where we have 8 billion today.

So why is Elon Musk worried about declining population?

It's because what's happening right now

is the beneath-the-surface trends are starting to catch up

to what we actually see on the surface,

where there's over 60 countries in the world

that have shrinking populations.

We have two parents.

So to keep population growth steady,

you would want to replace them with two children.

That would be a steady growth.

But in some countries, Singapore for example,

you only have one child born for those two parents.

So you can see how those populations

of those countries would start to shrink over time.

And that's happening especially in a lot

of high-income countries.

So the reason why somebody like Elon Musk would be concerned

about this is you end up with smaller generations over time,

meaning fewer producers and fewer consumers.

@shufflupaguss: I'm on a road trip right now,

and I'm wondering what's up with these empty small towns?

Are they ghost towns? Is depopulation real?

So depopulation is not only real,

there are a lot of governments

who are really worried about this

because of what it means for economic vitality

or national security.

Take China, for example:

obviously one of the world's biggest economies,

huge player on the international stage,

but also a rapidly shrinking population.

Look at a country like Italy

and how many of the villages are depopulating.

If you're in Europe, South Korea, Japan,

you're seeing areas of the country empty out.

We've seen pictures all over the newspapers

of towns and villages in Japan with ivy growing

through the windows from abandoned homes,

storefronts start to close.

These fertility rates are lower,

and then that means the population of these small towns

and cities is growing older and older

and then eventually dying out

without any young people there to replace them.

And you don't necessarily see people moving

from bigger cities all the way out to very small towns

and very rural areas

because there's no job opportunities there.

Now, you do see some retirees doing that.

Take a state like Maine, for example:

Most rural state in the United States actually has seen

an influx of retirees moving there,

but that's not because they're moving there

for job opportunities.

The United States itself is not shrinking overall,

but there are plenty of places within the United States

that are shrinking.

Now, we've had plenty of examples

of depopulation in the past.

I mean, think about Detroit

and the collapse of that auto industry there,

but we've not ever seen this scale of depopulation,

plus, of course, people often leaving these areas.

Because, you know, once an area starts to depopulate,

of course fewer people will be wanting to stay there.

The jobs leave, the community

and the vitality part of that disappears as well,

and so it can kind of accelerate that depopulation.

Here is a question from Quora.

What countries do most immigrants to America come from?

Well, top countries of origin for US immigrants in 2022,

this number here, 23% were from Mexico, 6% from India,

6% from China, 4% Philippines, and then El Salvador,

Vietnam, and Cuba, all 3%, and Korea 2%.

This has actually been changing over time.

Immigration from Mexico has really dropped over time.

Mexico's economy has been growing.

Their total fertility rate is actually the same

as the fertility rate in the United States, 1.6.

And so we've seen less Mexican immigration

to the US over time, as a proportion,

whereas we've seen countries to the south

of Mexico really increasing.

You know, think about gang violence

and instability in countries like El Salvador or Guatemala.

That's really been a driver of some

of that northward migration.

So those are the top countries of origin,

but if we look broader at the regions,

we see that Latin America's 50% of immigrants

to the United States in 2022,

but Asia was 31% of migrants to the US in that year.

Smaller percentages for Europe, 10%,

Africa, 6%, Canada and Oceania.

@maureen_jo: Why are people leaving California

for Texas and Arizona?

If we look at the way that the US population has changed

between the 2010 census and the 2020 census,

you still saw lots of growth in the population

in places in California,

and this pink here really shows you places

where you started to lose population.

So a lot of the US Northeast started

to see some emptying out.

But we saw during the pandemic that people were moving

to take advantage of states without income taxes.

Nashville really started to boom.

Tennessee is a state without an income tax.

Florida, similarly, a state without an income tax.

A lot of people started to move there.

Jobs would move there as well.

After the pandemic, we've really continued

to see growth in the US Southeast.

Between the middle of 2022 and the middle of 2023,

you saw the US Southeast grow by about 1.1%,

whereas the Northeast actually shrank,

while there were other regions in the US

that either barely grew or even shrank.

Craig'sbrotherBrian wants to know,

I've been to the most densely populated city in the world.

Have you? Do you know what city that is?

I do know, it's Manila in the Philippines

with approximately 46,000 people per square kilometer,

and I haven't been there yet.

DoomBro_Max asks, What made the world population increase

so drastically after 1900?

We had great improvements in public health, sanitation,

nutrition, antibiotics,

and that allowed those people who were born

to live into their reproductive ages.

So this chart really lays it out for us.

If we go way back in time, 200,000 years ago,

there's very little global growth.

Even as we go through time, 2000 BCE for example,

or year one, the global population,

the number of people here at any one point in time,

is really growing slowly,

and that's because our birth rates and our death rates,

those really matched each other.

But we start to see a major shift,

our first 1 billion people happening here

around the year 1800.

And then we hit our second billion a lot faster,

3, 4, 5, 6, 7, and now up to 8 billion people.

And so a lot of those increases are really happening

because we're living longer.

Dystopian Paradise wants to know,

In terms of age, what state has the oldest population?

The oldest state is Maine,

which has 23% of the population above age 65.

Classic Man wants to know,

Which state has the youngest population?

That state would be Utah,

which has 27% of the population under the age of 18.

You may notice that Utah is a home

to a pretty sizable Mormon population,

which tends to have higher births than other populations

in the United States.

@JustinLUngs: What's the biggest difference

between millennials and Gen Z?

The biggest difference is that globally, Gen Z,

or those people who were born from 1997 to 2012,

are larger than millennials,

who were born between 1981 and 1996.

But in the United States, millennials are larger than Gen Z.

Gen Z, though, is much more racially diverse.

So the percentage of Gen Z who are multiracial

is about 4% in the United States,

whereas it's only 2% among millennials in the US.

The share of people who are Hispanic

is actually about 4% higher among Gen Z in the US

than it is among millennials in the US.

@JMPFreedom: WTF is a sandwich generation?

Sandwich generation might sound delicious,

but it's pretty terrible.

It's those who are sandwiched between caring

for younger children and caring for older parents.

People are having children later in life.

There's a trend towards that in the United States,

in Japan, South Korea, Germany.

And so you could end up with a situation

where a woman is taking care of her one or two children

at the same time that she's caring for her aging parents,

who may live with her, or who need her to come by

and help with medical appointments or grocery shopping.

Some people will call this the panini generation, actually,

because these women are being squeezed in the middle.

From Reddit: What would happen

if all illegal immigrants were deported?

Well, in the United States,

we've got a stock of around 12 million people in the US.

Lots of things would probably happen.

There are certain industries in the United States

that actually are really heavily dependent

on that kind of labor.

So the agricultural industry, for example.

So you could expect having a harder time getting people

to fill those jobs, and then prices for food would rise.

The construction industry is much more heavily dependent

on that labor, and so we expect it'd take longer

to get houses built, and prices would rise for that as well.

In the United States,

there are over 16 million people who live in a household

with at least one undocumented person.

Over 7% of all kids in the United States

have at least one undocumented parent,

so we would see families being ripped apart

through these deportations.

Erik Kroll wants to know,

How do factors like income, race, geographic location,

et cetera, affect your life expectancy?

They affect it a lot. Let's look at income first.

So we have here a map of the US with the counties drawn out.

We can see here that some of the poorest counties

in the United States, like McDowell County, West Virginia,

with a median income of under $29,000 a year,

it has a life expectancy well below the US national average.

The same is true for Buffalo County, South Dakota,

with a median income of just over $30,000 a year.

East Carroll Parish, Louisiana,

also one of our poorest counties,

and Issaquena County, Mississippi,

life expectancy of under 75 years

and median household income of only over $17,000 a year.

It's not just powerful geography on the US scale,

it's also powerful at the global scale.

So here's a couple of different ways to slice it.

Let's stay over here with this yellow color for now.

Global life expectancy in 2024:

High-income countries, life expectancy is 81 years,

middle income, 73 years.

But low-income countries, life expectancy is only 65 years.

Most people know this, but, of course, sex matters.

Females tend to live longer than males,

76 years on average globally versus 71 years

for their male counterparts.

Mostly demographers will nail down

that men tend to be in riskier jobs.

When you get to the very oldest ages,

they're very heavily female, with women outliving men.

So that's something that countries either are

or should be talking about.

When it comes to healthcare, social security,

these things all go together.

They all affect the life expectancy of an individual.

And, of course, we aggregate that,

and they affect the life expectancy of a country as well.

@ChildishHambino wants to know,

What country has the lowest life expectancy?

I can't take another 62 years of this pish.

Okay, well, lowest life expectancy at birth

for males is in Chad, and that's at 53 years.

Lowest life expectancy at birth for females is in Nigeria,

and that is 55 years.

@AizazReal: What country has the highest life expectancy?

Well, the answer for males is tiny Monaco,

which has only 40,000 people,

but where males born can be expected to live to age 84.

Monaco and other small countries, like Lichtenstein,

they're really rich, they're small and rich.

And so we know that income level actually

is very highly correlated with life expectancy.

If you're thinking in terms of, you know,

countries you'd be more familiar with, those bigger ones,

in Japan, females live to about 87 years.

Isaac wants to know, People are living longer,

but are they living healthier at the same time?

Healthy life expectancy is one thing,

an overall life expectancy is another.

Healthy life expectancy is, you know,

how many years can you expect to live in good health

versus how many years you might live overall.

I think ideally for any of us,

you want that gap to be as narrow as possible.

So if we look at Haiti, for example,

you're only expected to live to age 56 healthy,

and then overall to age 64.

That's a gap of eight years.

This gap here really represents the end

of life lived in less than ideal health.

That may mean something as little as difficulty

with something like going up the stairs,

all the way to being bedridden.

It does affect how long you could work, for example.

How many years would you live healthy after retirement?

Could you have actually retired later?

That's something that's really relevant

to all these countries as their populations age.

So Haiti's at one end of the spectrum,

Japan's at the other end of the spectrum.

They could expect to live longer in good health, to age 74,

and then overall to age 84.

Now that's a gap of 10 years.

The United States, though, is an outlier

because our gap between healthy years lived

and overall years lived is 12 years.

So that means the average American lives the end

of their life many more years less than ideal health

than somebody in, say, even Bangladesh,

where it's only 10 years, or in Canada, where it's 11.

So when I think about how well will the US fair

as its population ages, I really worry

because it is very expensive to be sick

in the United States of America.

There's some real dings to the economy in our future

if we have this kind of gap,

12 years between our healthy life expectancy

and our overall life expectancy.

NewGuyUserName1:

What's the most populous country on Earth?

Well, the most populous country on Earth is India,

and the second most populous is China.

Both of them have about 1.4 billion people.

Far below that comes the United States,

followed by Indonesia and Pakistan.

If we count up the most populous countries, those five,

plus if we add in Nigeria and Brazil,

together, those would make up a little over half

of the world's population.

@aroyaliota: So how did China's one-child policy work out?

So the one-child policy from 1979

was a law the Chinese government put in place,

saying that mostly everyone could only have one child.

Naturally in a population,

there are about 105 boys born for every 100 girls.

That's just the way that it happens.

So that's represented by this orange line here.

And because there are really strong norms

of male preference, of son preference in China,

most of these families wanted to have a boy.

And that's why, when you have restriction to just one child,

and your first child is a girl,

we see that those that did have a second or third child,

you know, maybe those who were part

of ethnic minority populations

that were exempt from this one-child policy,

those second and third children had far more skewed

sex ratios at birth,

and that is because of sex-selective abortion.

Now, when I was born, which was more that way,

there were no ultrasound technology.

Like, my parents would not have known if I was a boy

or a girl before I came out.

These folks here, they could see in utero whether

or not this child would be a boy or a girl.

And many of them, as we see,

took measures to make sure that they would have a boy.

So when we're looking at a sex ratio at birth

for the third baby born, somewhere here,

around just a little bit before the year 2000,

there were nearly 160 males born for every 100 females born.

A tremendously skewed sex ratio at birth,

a lot different from the natural sex ratio of 105 males born

for every 100 females.

If these were people who were born just

before the year 2000,

they are now entering their late 20s.

And that means that there are millions more males

than there are females of these different ages.

So China is already a country

with well below replacement fertility rates

in a rapidly shrinking population.

It certainly does not help the population grow any faster,

that there are millions of missing females

of reproductive ages

that would have been born without the one-child policy.

AClodd asks, What change in demographics

are you concerned about?

One trend that people are concerned about

is a youthful population.

So this would be one where a huge proportion

of the population is of younger ages,

think children or teenagers.

A place like Niger or Mali,

having some of the youngest populations in the world,

they are at a greater risk of having coups,

more political instability.

But there are also opportunities associated with these types

of youthful populations.

Working-age populations are shrinking,

so a youthful population actually has lots of opportunity

for economic growth.

Wholesome_ecoli asks, What does demography mean?

At the broadest level,

demography is just studying human populations.

We're thinking about those human population changes.

And with those,

there are just three ingredients to think about:

fertility changes, mortality changes, and migration changes

or shifts in births, deaths, and migration.

Those in different combinations give you different outcomes

and gives us a lot to study.

Kiwi75 asks,

Let's look at which countries are growing fastest.

Growing economy is what we need.

The two fastest growing countries are South Sudan

and Chad, whose populations are growing at about 6% a year.

South Sudan and Chad are in Africa,

and Sub-Saharan Africa is a region of the world

with the highest fertility rates.

And so, one out of every four children in the world

will actually be African by the year 2050.

That's because fertility rates are lower in other regions

and they're higher in Sub-Saharan Africa.

Northern Africa, however,

does actually have lower fertility rates.

If we think about what would make a population grow,

it's having lots of people of reproductive ages

and a high number of births per person.

Over half of the world's projected population growth

between now and 2050 will come from just eight countries.

Now, that includes India,

which, interestingly enough, is a country

that has below replacement fertility rate,

fewer than two children born per woman on average.

So why is it still growing,

and why is it contributing so much

to world population growth?

That's some momentum of the past.

Those cohorts of women

of reproductive ages are larger from when fertility rates

were higher in the past.

So the average number

of children born per woman is smaller now,

but there are a lot of those women.

@MisaAlekseev: Why do Latin American migrants

to the United States have such a high birth rate?

After all, their birth rate is low in their homeland.

Or Latinos come to the United States

with a very high total fertility rate?

Well, you're right that, actually, in the homeland,

those fertility rates are lower.

If you look at this map,

those blue countries represent the two thirds

of Latin American countries

with below replacement fertility, so below two.

Even these handful in gray that are above,

they're not that far above, like Bolivia,

the total fertility rate of 2.5 children born per woman.

Think about someone who comes to the United States

as an immigrant.

They're typically of working ages, which also means

that they're typically of reproductive ages.

It just so happens that they're of those ages

where they're more likely to have children.

So it's not really true

that they have such a high birth rate,

it's just true that they tend to come of ages

where they are more likely to be having children.

We also know that when people stay in a country,

when an immigrant stays in a country, very quickly,

the norms shift to match that of the reproductive norms

around the native-born population.

So within a generation,

you usually see those immigrant fertility rates come

[swishes] right down to where the native-born population is.

@_Jan_P: How are illegal immigrants counted?

Well, first we want to think about how anybody is counted.

In the United States and many other countries,

there is a census around every 10 years or so.

But along the way, in between those times,

we have regular surveys, like the Current Population Survey

or the American Community Survey.

And so you can kind of put these together to get a snapshot

of what the population would look like.

If you want to know how many illegal

or irregular immigrants there are in a population,

you would take the number of legal migrants that you know,

and then you would take what you know from these censuses

about how many people are in an area,

and this residual or this difference is the estimate

of those people who are here outside the legal system.

And it is estimate.

Some people don't answer.

Sometimes you can think about somebody

who is in the country illegally,

lives in a household with people who are there legally.

And so the head of household might fill out the census

and say how many people are living there,

but it doesn't quite track with how many people are

in the area that you know through legal immigration means.

And so you can kind of look at those leftover numbers

to estimate that.

We always take these with a grain of salt,

but demographers do use all their context clues

and use all the data to try to estimate that.

@WeeklyHumorist: A new study says that in the future,

most of the world will live in mega cities

and their office will be in any of the windows stools

at Starbucks that can reach an outlet.

Well, this is certainly what sci-fi would tell us

about mega cities, which is amalgamations

of population in areas of 10 million or more.

I don't necessarily think it's the case,

but it will depend on where you are in the world.

I mean, there's countries like Bangladesh, for example.

They just, frankly, don't have any extra space,

so we do see really densely populated areas.

There are people who are leaving rural areas for urban areas

to seek better economic opportunity.

Year 1800, for example, only about 3%

of the world's population lived in urban areas.

Now we have over 58%

of the world's population living in urban areas.

So generally, there is a trend

towards moving in that direction.

We also see the opposite.

We had seen during the pandemic,

some people leaving those urban cores for smaller cities

or suburban areas.

TBD on how that shakes out in the future.

@RodT3: How do mortality rates

in the US compare to other countries?

So with that, you're asking about the number

of people dying per 1,000.

So if you're Japan, you would have a higher mortality rate

because you have a lot of older people than maybe a country

that actually has a less healthy population.

I bet what you really want to know about is life expectancy,

especially life expectancy at birth.

How many years would a person born today

be expected to live?

And in the United States,

life expectancy at birth is about 78 years old.

Even Canada, our neighbor to the north,

has a life expectancy at birth of 82 years.

So US life expectancy has not really been keeping pace

with increases the way that we would expect it to,

and that's because health in the US is, frankly, really bad.

And in terms of access to healthcare,

that can be really uneven from rural to urban areas

or by race as well.

A non-Hispanic Black woman in the United States is three

and a half times more likely to die during pregnancy

or shortly thereafter than a non-Hispanic white woman.

So all of these things combined,

the opioid crisis, another factor in there,

these drive US life expectancy lower.

From Reddit: RoninSolutions says,

Ukraine's population is nose diving.

Can anything be done?

How can Ukraine build a future

in the face of ominous population statistics?

That's a great question.

About 10 million people have left since the war started,

and this is a country that already had a history

of immigration or emigration,

people leaving for opportunities in Western Europe,

for example, for work.

It's also a country that already had well

below replacement fertility rates.

So with fewer births and lots of people leaving,

they are having a serious situation with a population

that is shrinking,

and there's not really much that can be done about it.

We know from countries around the world,

everywhere from Germany to Canada to Japan,

that governments can play very little role

in raising fertility rates

through things like tax incentives or, you know,

paying for different credits for having children.

So not much can be done on that.

When the war ends and the country begins to rebuild,

hopefully that will open up lots of economic opportunity,

and the peace there will attract some people to come back.

Some of those 10 million people may come back

and start to build lives there.

So those are all the questions for today.

I hope you have seen that demography

is a really powerful lens

with which to view this complex world of 8 billion people.

Thanks for watching Population Support.

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