IH GRADE 10

IB MYP Grade 10 Individuals & Societies – Population Change Revision Notes

1. Population Growth

Population growth is the increase or decrease in the number of people living in a country over time. It is influenced by births, deaths, immigration, and emigration. A population grows when more people are added than lost and decreases when more people leave or die than are born. Population growth affects the demand for housing, jobs, healthcare, education, and natural resources.

Rapid population growth can benefit a country by creating a larger workforce and increasing economic activity. However, it can also lead to overcrowding, unemployment, pollution, and pressure on public services. Slow or negative population growth may reduce pressure on resources but can result in labour shortages and an ageing population.

2. Birth Rate

The birth rate, also known as the Crude Birth Rate (CBR), is the number of live births per 1,000 people in one year. Countries with high birth rates are usually developing countries where families are larger, access to contraception is limited, and children are often needed to support the household. Countries with low birth rates are generally more developed, with better education, improved healthcare, urban lifestyles, and greater career opportunities for women.

A high birth rate increases the number of young dependants, creating greater demand for schools, healthcare, housing, and jobs. A low birth rate may reduce pressure on resources but can contribute to an ageing population and a smaller future workforce.

3. Death Rate

The death rate, or Crude Death Rate (CDR), is the number of deaths per 1,000 people in one year. Death rates are influenced by healthcare, nutrition, sanitation, disease, natural disasters, and conflict. Countries with good healthcare systems and high living standards usually have lower death rates, while poorer countries often experience higher death rates due to limited medical care and poorer living conditions.

A high death rate can reduce population growth and lower life expectancy. A low death rate contributes to population growth and often reflects improvements in healthcare, clean water, sanitation, and nutrition.

4. Natural Increase

Natural increase is the difference between the crude birth rate and the crude death rate. It measures population change caused only by births and deaths and does not include migration. When the birth rate is higher than the death rate, natural increase is positive. When the death rate is higher than the birth rate, natural increase is negative.

Countries with a positive natural increase often have growing populations and younger workforces but may face pressure on housing, healthcare, and education. Countries with a negative natural increase usually experience ageing populations, labour shortages, and increasing costs for pensions and healthcare.

Case Study – China: China currently has a negative natural increase because its birth rate has fallen below its death rate. This is mainly due to an ageing population, low fertility rates, and changing lifestyles. The government introduced the two-child and later the three-child policy to encourage higher birth rates and reduce future labour shortages.

5. Population Structure

Population structure refers to the composition of a population based on age and sex. It helps geographers understand how many people are children, working-age adults, or elderly. Population structure influences a country's demand for schools, jobs, healthcare, and pensions and is commonly shown using a population pyramid.

A youthful population has many children and young people, while an ageing population has a high proportion of elderly people. The population structure changes over time as birth rates, death rates, and life expectancy change.

6. Population Pyramids

A population pyramid is a graph showing the age and sex structure of a population. Males are shown on the left and females on the right, while age groups are displayed from youngest at the bottom to oldest at the top. The shape of the pyramid provides information about birth rates, death rates, life expectancy, and future population trends.

A wide base indicates high birth rates and a youthful population, while a narrow base suggests low birth rates. A wider top shows a longer life expectancy and an ageing population. Population pyramids help governments plan for future needs such as schools, healthcare, housing, and pensions.

7. Age Structure

Age structure refers to the proportion of people in different age groups within a population. It is usually divided into three groups: young dependants (0–14 years), working-age population (15–64 years), and elderly dependants (65+ years). Understanding a country's age structure helps governments plan for future needs such as schools, employment opportunities, healthcare, and pensions.

Countries with a young population often experience rapid population growth and need more investment in education and jobs. Countries with an ageing population require greater spending on healthcare, pensions, and elderly care and may face labour shortages as more people retire.

8. Dependency Ratio

The dependency ratio measures the number of dependants compared with the working-age population. It includes both young dependants and elderly dependants. A high dependency ratio means fewer working people are supporting a larger dependent population, increasing financial pressure on families and governments.

A high youth dependency ratio increases demand for schools, childcare, and healthcare. A high elderly dependency ratio increases spending on pensions, hospitals, and elderly care. Countries aim for a balanced dependency ratio to maintain economic stability.

9. Sex Ratio

The sex ratio is the number of males compared to females in a population, usually expressed as the number of males per 100 females. A balanced sex ratio helps maintain stable population growth and supports future economic development. Factors such as migration, war, disease, and government policies can affect the sex ratio.

An unbalanced sex ratio may lead to social and economic challenges, including difficulties in finding marriage partners, labour shortages in certain sectors, and changes in population growth patterns.

10. Demographic Transition Model (DTM)

The Demographic Transition Model (DTM) explains how a country's population changes as it develops economically and socially. It consists of five stages that show changes in birth rates, death rates, and natural increase over time.

Stage 1 – High Stationary

Both birth rates and death rates are very high, so population growth is slow. Poor healthcare, disease, famine, and limited sanitation keep death rates high, while families have many children to compensate for high infant mortality. Very few countries remain in this stage today.

Stage 2 – Early Expanding

Death rates fall rapidly due to improvements in healthcare, sanitation, clean water, and food supply, while birth rates remain high. This causes rapid population growth and creates a youthful population. Many developing countries have experienced this stage.

Stage 3 – Late Expanding

Birth rates begin to decline as education improves, women gain more employment opportunities, access to contraception increases, and urbanisation becomes more common. Population growth continues but at a slower rate because the gap between birth and death rates becomes smaller.

Stage 4 – Low Stationary

Both birth rates and death rates are low, resulting in slow and stable population growth. Countries in this stage usually have strong economies, advanced healthcare, and high standards of living. Most developed countries are in Stage 4.

Stage 5 – Declining

Birth rates fall below death rates, leading to negative natural increase and an ageing population. Countries in this stage often face labour shortages, rising pension costs, and increased demand for healthcare. Governments may introduce policies to encourage families to have more children. China and Japan are examples of countries experiencing Stage 5 characteristics.

11. Migration

Migration is the movement of people from one place to another, either within a country or across international borders. People migrate for economic, social, political, or environmental reasons. Migration can be permanent or temporary and may be voluntary or forced.

Migration changes population size and structure. It can provide workers for countries with labour shortages while also creating challenges such as pressure on housing, transport, healthcare, and public services.

12. Internal and International Migration

Internal migration is the movement of people within the same country. A common example is rural-to-urban migration, where people move to cities for better jobs, education, and healthcare.

International migration is the movement of people from one country to another. This may occur because of employment opportunities, education, family reunification, conflict, or natural disasters.

13. Voluntary and Forced Migration

Voluntary migration occurs when people choose to move to improve their quality of life, such as finding better jobs, education, or living conditions. Economic migrants and international students are common examples.

Forced migration occurs when people have no choice but to leave because of war, political persecution, natural disasters, or environmental hazards. Refugees and asylum seekers are examples of forced migrants.

14. Push and Pull Factors

Push factors are the reasons that force people to leave their home country or region. Common push factors include unemployment, poverty, war, political instability, natural disasters, and poor healthcare.

Pull factors attract people to a new location. These include better job opportunities, higher wages, quality education, improved healthcare, political stability, safety, and a higher standard of living.

15. Lee's Migration Model

Lee's Migration Model explains migration using four main factors: push factors, pull factors, intervening obstacles, and personal factors. Push factors encourage people to leave their home, while pull factors attract them to another place. Intervening obstacles, such as high travel costs, strict immigration laws, language barriers, or long distances, may prevent migration. Personal factors mean that individuals respond differently to the same circumstances depending on their age, income, education, and family situation.

16. England & Wales Case Study

England and Wales are examples of countries with an ageing population. Low birth rates, increasing life expectancy, and better healthcare have resulted in a growing proportion of elderly people. This has increased demand for pensions, hospitals, healthcare workers, and elderly care services. At the same time, fewer young people are entering the workforce, creating labour shortages in some sectors.

Despite these challenges, an ageing population also brings benefits. Older people contribute valuable skills and experience, many continue working beyond retirement age, and the "silver economy" creates demand for new products and services aimed at older adults. The government continues to invest in healthcare, encourage healthy ageing, and adapt public services to meet the needs of an older population.

17. China Case Study

China is an example of a country experiencing negative natural increase and an ageing population. For many years, the One-Child Policy reduced birth rates and slowed population growth. Although this policy helped reduce pressure on resources, it also created long-term challenges, including a shrinking workforce and an increasing elderly population.

Today, China's birth rate is lower than its death rate, resulting in negative natural increase. This has increased pressure on healthcare, pensions, and the economy. To encourage population growth, the government replaced the One-Child Policy with the Two-Child Policy in 2016 and later introduced the Three-Child Policy in 2021. However, birth rates remain low because of the high cost of raising children, urban lifestyles, and changing social attitudes.

18. Population Policies

Population policies are strategies introduced by governments to influence population growth. They are used to either increase or decrease birth rates depending on a country's demographic needs.

Antinatalist policies aim to reduce birth rates in countries experiencing rapid population growth. These policies may include limiting the number of children, improving access to contraception, and promoting family planning. China's former One-Child Policy is a well-known example.

Pronatalist policies encourage families to have more children. Governments may provide financial support, paid parental leave, free childcare, housing assistance, or tax benefits. These policies are common in countries with ageing populations and low birth rates.

19. Case Study – Canada (Migration)

Canada is one of the world's leading immigration countries and has a positive net migration rate. It attracts migrants because of its strong economy, high quality of life, political stability, excellent healthcare, and education system. Skilled migration programmes help fill labour shortages and support economic growth.

Although immigration benefits Canada's economy, rapid population growth also increases demand for housing, healthcare, schools, and public transport. Major cities such as Toronto and Vancouver face housing shortages and rising living costs because of increasing population.

20. Case Study – Syria (Migration)

Syria is an example of a country with high emigration due to conflict. Since the civil war began in 2011, millions of Syrians have been forced to leave their homes because of violence, insecurity, and destruction. Many have become refugees in neighbouring countries or Europe.

The loss of working-age adults has reduced Syria's workforce and slowed economic development. However, migrants often send remittances back to their families, providing an important source of income for those who remain.

21. Impacts of Migration

Migration has both positive and negative impacts on source and destination countries.

For the destination country, migration helps fill labour shortages, increases cultural diversity, and supports economic growth. However, it can also place pressure on housing, transport, healthcare, and education.

For the source country, migration reduces unemployment and increases remittances sent home by migrants. On the other hand, it may result in brain drain, where skilled workers leave, slowing economic development and reducing the availability of trained professionals.

22. Key Terms

Population Growth: The increase or decrease in a country's population due to births, deaths, immigration, and emigration.

Birth Rate (CBR): The number of live births per 1,000 people in one year.

Death Rate (CDR): The number of deaths per 1,000 people in one year.

Natural Increase: The difference between the birth rate and death rate.

Migration: The movement of people from one place to another.

Immigration: Moving into a country.

Emigration: Leaving a country.

Net Migration: The difference between immigration and emigration.

Population Structure: The composition of a population by age and sex.

Dependency Ratio: The proportion of dependants compared with the working-age population.

Population Pyramid: A graph showing the age and sex structure of a population.

Push Factors: Reasons that force people to leave a place.

Pull Factors: Reasons that attract people to a new place.

Intervening Obstacles: Challenges that make migration more difficult, such as distance, cost, language barriers, or immigration laws.