Demographic transition | Society and Culture | MCAT | Khan Academy

Summary

The demographic transition model outlines the shift from high to low birth and death rates as countries industrialize. It consists of five stages: from high rates with a stable population in Stage 1, to a growing population in Stages 2 and 3 due to declining death rates and later, falling birth rates. Stage 4 sees a stabilization with balanced low rates, while Stage 5 remains speculative, with theories ranging from population decline to potential growth or even off-planet colonization.

Takeaways

• 🌟 Demographic transition is a model that describes how a country's population changes over time, moving from high to low birth and death rates.
• 📈 The growth rate is a measure of population change over a period, calculated by births plus immigration minus deaths and emigration.
• 🌱 Most countries currently have a positive growth rate, meaning their populations are increasing due to various economic, religious, and cultural factors.
• 🏭 Industrialized countries often have lower birth rates as children are no longer seen as economic assets but as individuals who require education and care.
• 🌐 The demographic transition model has five stages, starting from high birth and death rates to stabilization and potential decline.
• 🏥 Stage 1 is characterized by high birth and death rates due to limited birth control and poor health conditions.
• 🌱 Stage 2 sees a rise in population as death rates drop due to improvements in health and sanitation.
• 📉 Stage 3 is marked by declining birth rates due to access to contraception and a shift towards smaller families.
• 🔄 Stage 4 represents stabilization where both birth and death rates are low, seen in many developed countries.
• 🤔 The future of population growth after Stage 4 is uncertain, with theories ranging from stabilization to decline or even a resurgence in growth.

Q & A

What is the demographic transition model?

The demographic transition model is a theory that describes the changes in a country's population as it moves from high birth and death rates to low birth and death rates, eventually stabilizing the population. This transition often occurs as a country becomes more industrialized.

How does a country's growth rate relate to its population changes?

A country's growth rate measures the change in population over a specific time period, considering the number of births, deaths, immigrants, and emigrants. A positive growth rate indicates an increase in population, while a negative growth rate indicates a decrease.

Why do less developed countries often follow the demographic patterns of more developed countries?

Less developed countries tend to follow the demographic patterns of more developed countries because they often look to them for advancements in technology, healthcare, and social policies, which can influence birth and death rates.

What factors contribute to a positive growth rate in a country?

A positive growth rate in a country can be influenced by economic benefits of having children, government incentives for larger families, religious beliefs promoting large families, and cultural values that place prestige on having children.

What are the five stages of the demographic transition model?

The five stages of the demographic transition model are: 1) High birth and death rates with a stable population, 2) Declining death rates and a growing population, 3) Declining birth rates as society becomes more industrialized, 4) Low and balanced birth and death rates with a stable population, and 5) Speculative stage where population may stabilize, decrease, or increase again.

What is a stationary population pyramid and how does it relate to Stage 1 of the demographic transition model?

A stationary population pyramid is a model that shows a stable population with a high number of births and deaths, resulting in a balanced age distribution. This is characteristic of Stage 1 of the demographic transition model, where birth and death rates are both high.

How does the population pyramid change from Stage 1 to Stage 2 in the demographic transition model?

In Stage 2, the population pyramid shifts from a stationary to an early expanding shape as death rates drop due to improvements in health and sanitation, while birth rates remain high, leading to a growing population.

What factors lead to a decline in birth rates during Stage 3 of the demographic transition model?

During Stage 3, birth rates begin to fall due to increased access to contraception, changing social trends toward smaller families, better healthcare, and industrialization, which reduces the economic need for large families.

What characterizes Stage 4 of the demographic transition model?

Stage 4 is characterized by low and balanced birth and death rates, leading to a stable population. This stage is marked by improvements in contraception, a high percentage of women in the workforce, and a focus on careers over having children.

What are the possible outcomes for the world population after Stage 4 of the demographic transition model?

After Stage 4, the possible outcomes for the world population include stabilization due to resource constraints, a decrease as birth rates continue to fall below death rates, or an increase in population due to high standards of living and fertility rates.

Outlines

00:00

🌱 Demographic Transition and Population Growth

This paragraph introduces the concept of demographic transition, which is a model that explains how a country's population changes over time. It discusses the shift from high birth and death rates to low rates, leading to population stabilization, typically seen in industrialized countries. The growth rate, which measures population change over a period, is explained using the example of a hypothetical country 'Zed'. Factors influencing population growth, such as economic benefits, government incentives, religion, and cultural influences, are also highlighted. The paragraph sets the stage for understanding the five stages of the demographic transition model.

05:01

🌟 Stages of Demographic Transition

This paragraph delves into the five stages of the demographic transition model. Stage 1 is characterized by high birth and death rates, typical of pre-18th century countries. Stage 2 marks the beginning of population growth due to falling death rates, seen in 19th century Western Europe post-Industrial Revolution. Stage 3 witnesses a decline in both birth and death rates due to better healthcare and industrialization, observed in some South American and Middle Eastern countries. Stage 4 represents stabilization with low birth and death rates, exemplified by countries like the United States and Australia. The final stage is speculative, with theories suggesting possible stabilization, decrease, or increase in population, influenced by factors like resource scarcity, individualism, and government policies. The paragraph concludes with the uncertainty of future demographic trends.

Keywords

💡Demographic Transition

Demographic transition refers to the model of population change in a country as it moves from high to low birth and death rates. This concept is central to the video's theme, illustrating the shift from traditional to modern societies. The video describes how countries progress through stages of high birth and death rates to stabilization, often influenced by industrialization and economic development. The demographic transition is exemplified in the script through the hypothetical country 'Zed,' demonstrating how population growth rates are calculated and how they change over time.

💡Growth Rate

The growth rate is a measure of the change in a country's population over a specific period. It is a key concept in the video, as it helps to quantify population dynamics. The video explains that the growth rate is calculated by considering births, deaths, immigration, and emigration. For instance, the country 'Zed' starts with one million people, and the script details how the addition of births and immigrants and the subtraction of deaths and emigrants contribute to the year-end population, thus affecting the growth rate.

💡Industrialized Countries

Industrialized countries are nations with advanced economies characterized by large-scale industrial production. In the context of the video, these countries often exhibit low birth and death rates, which is a sign of demographic transition. The video suggests that less developed countries tend to follow the patterns of more developed ones, implying that industrialization plays a role in population stabilization. Examples from the script include the United States and Australia, which are in the fourth stage of demographic transition with low growth rates.

💡Birth Rates

Birth rates are the ratio of live births to the total population in a given area over a certain period. They are a critical component of the demographic transition model. The video explains that in the early stages of the model, birth rates are high due to limited birth control and economic benefits of having more workers. However, as countries develop and become more industrialized, birth rates decrease due to better access to contraception and changing social norms, as illustrated by the declining birth rates in Stage 3 of the demographic transition.

💡Death Rates

Death rates are the ratio of the number of deaths to the total population in a given area over a certain period. They are inversely related to the progress of demographic transition. The video outlines that high death rates are common in less developed countries due to factors like poor nutrition and disease. As countries industrialize and improve health care, death rates decrease, contributing to population growth until they eventually stabilize, as seen in the transition from Stage 2 to Stage 4.

💡Population Pyramid

A population pyramid is a graphical representation of the age and gender distribution within a population. It is used in the video to visualize the demographic changes that occur during the stages of demographic transition. The video describes how the shape of the pyramid changes from a high stationary pyramid in Stage 1, to an expanding pyramid in Stage 2 and 3, and finally to a low stationary pyramid in Stage 4, reflecting the shift from high to low birth and death rates.

💡Economic Benefits of Children

The economic benefits of children refer to the financial advantages that come from having children, such as additional labor for family work. The video discusses how in some countries, children are seen as a source of support for the family, which can contribute to higher birth rates. This concept is tied to the video's theme by showing that economic factors influence population growth, as seen in countries where the government provides incentives for childbearing.

💡Religion and Population Growth

Religion can influence population growth through its teachings and cultural practices. The video points out that some religions promote large families, which can lead to higher birth rates. This is connected to the video's theme by showing how cultural and religious factors can impact demographic trends. For example, the script mentions that some religions forbid the use of contraceptives, which can result in larger family sizes.

💡Cultural Influences on Family Size

Cultural influences on family size refer to the societal norms and values that encourage or discourage large families. The video explains that in some cultures, having children is associated with prestige and the continuation of family traits and values. This concept is integral to the video's narrative as it demonstrates how cultural practices can shape population dynamics, contributing to either higher or lower birth rates depending on the cultural context.

💡Malthusian Theorem

The Malthusian Theorem, named after Thomas Malthus, suggests that population growth will outpace the growth in food production, leading to a crisis. The video speculates on this theorem as a potential future scenario where the world population stabilizes due to resource constraints. This concept is relevant to the video's theme as it presents one of the theories about the ultimate outcome of population growth, suggesting that at some point, the population may have to stabilize or decrease.

💡Anti-Malthusian Theorem

The Anti-Malthusian Theorem is a counterpoint to the Malthusian Theorem, suggesting that technological advancements and social changes can lead to a decrease in population growth. The video mentions this theorem as a possible reason for future population decline, where couples may choose to have fewer children or delay childbearing. This concept is important in the video's discussion of potential future demographic trends, highlighting the role of individual choices and societal changes in shaping population dynamics.

Highlights

Demographic transition is a model that predicts changes in a country's population as it moves from high to low birth and death rates.

Population stabilization typically occurs in industrialized countries due to their advancements influencing less developed ones.

Most countries currently have a positive growth rate, indicating a continuously increasing population size.

Growth rate is defined as the measure of population change over a specific time period.

The example of 'Zed' illustrates how to calculate population growth by accounting for births, deaths, immigration, and emigration.

Positive growth rates are influenced by economic benefits of child labor and government incentives for larger families.

Religion often promotes large families, which can impact population growth rates.

Cultural influences, such as the prestige of having children, can also contribute to higher birth rates.

The demographic transition model consists of five stages, starting with high birth and death rates.

Stage 2 of the model is characterized by a drop in death rates due to improvements in health and sanitation.

In Stage 3, both death and birth rates begin to decline due to access to contraception and a shift towards smaller families.

Stage 4 represents a stabilization of the population with low and balanced birth and death rates.

The final stage of the model is speculative, with theories ranging from population decline to potential stabilization or resurgence.

Malthusian Theorem suggests a potential global crisis due to resource depletion, which could force population stabilization.

Anti-Malthusian Theorem posits that higher standards of living could lead to smaller families and a decrease in population.

Government policies, such as China's one-child policy, aim to control population growth and conserve resources.

Demographic transition reflects the shift from high to low birth and death rates with industrialization, but the future trajectory remains uncertain.

Transcripts

Voiceover: Demographic transition is a model that

changes in a country's population.

It states that the population will eventually stop

growing when the country transitions from high

birth rates and high death rates to low birth rates

and death rates, stabilizing the population.

This stabilization often occurs in industrialized

countries, because less developed countries tend

to rely on and follow the more developed countries

for their advancements.

Right now, most countries have a positive growth

rate, which means their population keeps getting

bigger.

First, let's pin down what the growth rate is.

Growth rate measures how much the population

of a country grows or shrinks over some time period.

For example, let's take a look at this country.

I'm going to call it "Zed".

Zed, here, had one million people at the beginning

of the year.

If we want to know the growth rate of the population

of Zed for the year, we count how many people were

added to the population and how many people were

removed.

The number of people added includes the number

of births and the number of people who immigrated

into the country during that year.

Let's say 20,000 babies were born this year and

50,000 people moved to Zed from other countries.

Then you have to subtract from this number how

many people were removed from the population,

so the number of deaths and the number of people

who emigrated from the country during that year.

Let's say, during the year, 15,000 people died and

5000 people moved out of Zed.

From here, it's pretty easy to figure out the

population of Zed at the end of the year.

Started with one million, add 20,000 births and

50,000 immigrants and subtract 15,000 deaths and

5000 emigrants, which gives us 1,050,000 people

at the end of the year.

If we want the growth rate over this year, all you

need to do is take that total current population,

subtract the total number of people in the country

at the beginning of the year, and then divide by that

number again.

Multiply it by 100 and you turn it into a percentage.

Now you have your growth rate.

So now you can see why, when we say there's a

positive growth rate, that means that the population

is now bigger than the population in the past.

But why do most countries currently have a

positive growth rate?

There are economic benefits, because children can

work to help support the family.

Sometimes, the government even provides incentives

to families for each child, like in Japan, where birth

rates are very low.

Religion also influences population growth, because

it often promotes large families, which increase the

number of people in their faith and encourages

stronger community.

Some religions will even forbid the use of

contraceptives by their followers, pretty much

ensuring large families.

And there are cultural influences that promote

large families, too.

Having children means that a person is passing

down their own family's traits and values.

There's a kind of prestige that goes along with

having children.

Okay, now let's dive into the demographic transition

model.

There are five stages to the demographic

transition model.

In Stage 1, a country has high birth rates, often due

to limited birth control and the economic benefit

of having more people to work.

They also have high death rates, due to poor

nutrition or high rates of disease.

It is believed that most countries were at Stage 1

until the 18th Century, when death rates in western

Europe began to fall.

You can see this type of population modeled by a

high stationary population pyramid, with a high

birth rate.

This pyramid shows the number of people alive in a

population, depending on age and gender.

As you can see, the Stage 1 stationary population has

many births, creating a large young population, as

well as many deaths, creating a small older

population and keeping the over all population

fairly stable.

The second stage is seen in the beginnings of the

developing country.

The population begins to rise as death rates drop,

because of improvements in health and sanitation

and the availability of food.

This trend can be seen in western Europe in the

19th Century, after the Industrial Revolution.

The birth rates are about the same as they were in

Stage 1, though, so the over all population begins

to grow.

This is an early expanding population pyramid.

You have high birth rates still, see, lots of young people,

but the death rate is declining, so you have more

older people, making this nice pyramid shape.

In Stage 3, the death rates continue to drop, but

at the same time, birth rates also begin to fall

because of access to contraception and a changing

social trend toward smaller families.

The society has better health care and is becoming

more industrialized by this point, meaning there are

fewer childhood deaths and also the kids don't need

to work, or aren't allowed to work by law any more.

Having lots of children isn't economically beneficial

any more, as the kids are sent to school, rather than

working to support the family.

Many countries in South America and the Middle East

have such declining birth rates.

This population is still expanding, but at a slower

rate.

You can see in this late expanding population pyramid,

that, as birth rates decline, there are fewer young

people and, with the already-declining death rates,

people are living longer lives.

The population finally stabilizes in Stage 4 of

the demographic transition model, where both

birth rates and death rates are low and balance each

other out.

By this point, the population is rather large, because

it had been growing up until this point.

The low birth rates are due to a combination of

improvements in contraception as well as the high

percentage of women in the workforce and the fact

that many couples choose to focus on careers over

having children.

Countries like the United States or Australia are in

Stage 4 right now.

The population can be modeled by a low stationary

pyramid, with low birth rates and low death rates,

as well as a longer life expectancy.

The fifth and final stage is only a speculation.

There are few theories as to what happens next.

Some believe that the world population will be

forced to stabilize as the Malthusian Theorem

suggests.

Perhaps we will run out of resources, and there will

be a global food shortage.

Already, of the more than seven billion people on our

planet, there are about one billion world-wide who

suffer from hunger and malnutrition.

The world population continues to increase but,

perhaps, we won't be able to maintain the natural

resources at the rate we are going for how many

people live on this planet, which Malthusians believe

will lead to a major public health disaster and

force the population to remain stable.

Or, perhaps, the population will begin to decrease

after it stabilizes, continuing the trend of decreasing

birth rates until it drops below the death rate.

With more people dying than being born, there

would be a negative growth rate.

This results in a constrictive population pyramid,

where there are fewer young people than old.

Perhaps this will be because of a rise in individualism

or, perhaps, as the anti-Malthusian Theorem states,

this will be because couples only want to have one

child or they have children later in life.

Some evidence shows that a better standard of

living promotes smaller families, as children become

an economic burden, rather than a source of

financial support.

Industrialized nations often have better education

and access to health care, which contribute to more

reproductive choices.

Some governments, like in China, are even adopting

policies that encourage small families to slow their

population growth and save resources.

Or, on the other hand, perhaps the population will

begin to grow again after the stabilization of the

fourth stage.

Some evidence shows that high standards of living

actually promote fertility and a higher birth rate.

There's only one real way for us to find out what

will happen next and we'll have to wait it out

and see where the world is in a century or two.

So, I'll see you there, right?

To sum it up, demographic transition is a shift from

high birth and death rates to low birth and death

rates as a country becomes industrialized, but what

will happen after that is impossible to tell.

Will the population stabilize?

Will it decrease, will increase?

Will we move off-planet and colonize a world

around a distant star?

We could only guess for now.