Dynamics of Population | CBSE Class 8 Geography Notes

This note covers demography, population size and distribution, birth and fertility rates, mortality, migration, demographic transition, population composition, population pyramids, India's demographic dividend, and the challenges of an ageing population.

What is demography, and why do we study population?

Definition: Demography is the study of human population, its size and composition, and how these features change over time through births, deaths and the movement of people.

Population composition, also called population structure, means the characteristics that make up a population. These include age, gender, education, occupation and religion. Knowing how many people live in a place is therefore only one part of understanding its population.

How does demographic information help planning?

Working-age population generally refers to people aged 15 to 64 years, considered the most productive in economic output and participation in work. This describes an age group, rather than saying that every person in that group has a job.

A place with many children needs more schools. A place with a higher proportion of elderly people needs more healthcare facilities. A larger young working-age population creates a greater need for jobs that provide an income.

Governments use population information to plan infrastructure, the facilities needed for everyday life, such as schools, hospitals, roads and housing. They also plan water supply, energy and waste management. Businesses consider customers' age, gender and income when designing products to meet their needs.

What information does a census collect?

A census collects, compiles, analyses and shares demographic, economic and social information about all people in a country or a defined part of it at a particular time. In India, it is generally conducted every 10 years.

It records information such as age, gender, marital status, education, languages, religion, family size, occupation, employment and income. Together, these details help governments understand both population size and people's different needs, so that resources can be allocated and managed better.

How have world and Indian population totals changed?

India surpassed China in 2023 to become the world's most populous country. Indians constitute around 17 per cent of the world's population. Per cent means out of every hundred. The word population here refers to the number of people, rather than their age or employment characteristics.

World population rose from 2.5 billion in 1950 to 8.2 billion in 2025. A million means 1,000,000; a billion means 1,000 million. It is expected to reach 9.7 billion by 2050. These future figures are projections, meaning estimates based on present trends.

Why did population grow rapidly?

From the 1950s, medical advances and wider access to better water and sanitation helped people survive and live longer. Fewer children died from diseases, while the benefits of economic prosperity reached more people in several countries. Improved healthcare largely explains the rising world population.

However, growth has slowed over time. Projections place the world population peak at 10.3 billion by the mid-2080s, followed by gradual decline as birth rates fall. Birth rate usually means live births per 1,000 people in a year. A projection describes an expected future, rather than a count already completed.

How is population distributed across regions?

Coloured circles on a world map label Asia at 4.8 billion, Africa at 1.5 billion, Europe at 744.3 million, Northern America at 387.5 million, Latin America and the Caribbean at 66.78 million, and Australia and Oceania at 46.6 million.

See Fig. 6.6 in your NCERT textbook

Population change differs across countries. China, Japan and Italy already have shrinking populations. India's population is growing for now, while several African countries, including Nigeria and Ethiopia, continue to grow rapidly.

The following population totals, measured in millions, show India's growth over time.

How do birth and fertility rates affect population?

A country's population reflects years of births, deaths and movement into and out of the country. An indicator is a measure used to understand something. Birth rate and fertility rate are closely linked demographic indicators, but they measure different things.

Definition: Birth rate measures births during a specified period, usually expressed as the number of live births per 1,000 people in a year. Fertility rate is the average number of children a woman is likely to have during her lifetime.

How do these measures differ?

Birth rate relates births to the whole population during a year. Fertility rate concerns the average number of children per woman over her lifetime. Do not treat either as a simple count of babies without its population base or time period.

If many babies are born, birth rate is high and population grows faster. With fewer births, population might grow slowly or even begin shrinking over time. Falling fertility means women have fewer children, so birth rate also drops and population growth slows.

What is replacement level fertility?

A fertility rate of 2.1 is often called replacement level fertility: the number of children needed to replace the parents in the population. It represents about two children per woman on average and is important for maintaining a stable population.

Above 2.1, population is likely to grow; below 2.1, it might shrink over time. These qualifications matter. A lower fertility rate does not mean that the total population immediately becomes smaller. India combines continued population growth with fertility below replacement level.

Why are families becoming smaller, and how does education matter?

One important reason for falling fertility and birth rates is better access to quality education, especially for girls. As more women gain formal education and enter formal jobs, they are more likely to marry later and have fewer children.

Urbanisation means the growth of towns and cities. Rapid urbanisation brings a high cost of living, particularly in cities, and people prefer smaller families. Education, employment and living costs therefore help explain changing decisions about the number of children.

What do fertility and literacy figures show?

Literacy means the ability to read and write. The literacy rate among women expresses the literate share of the female population used in that measure. In the table, % means per cent, or out of every hundred; UT means Union Territory.

Bihar has the highest fertility rate and lowest female literacy rate among these entries. Delhi has the highest female literacy rate and shares the lowest fertility rate with Punjab. The figures support discussion of the relationship between education and family size.

The relationship is not an exact rule for every pair. Uttar Pradesh has both higher literacy and higher fertility than Jharkhand in this table. Education is an important factor, but the table should not be read as a mechanical formula.

How has fertility changed in India?

From 1952 onwards, campaigns such as “Hum do humare do” encouraged families to have no more than two children. India's fertility rate declined from 5.7 in 1950 to 1.9 in 2025, although its population is still growing.

The important distinction is between fewer children per woman and fewer people overall. Fertility describes family-size patterns, while total population also reflects the continuing effects of births, deaths and movement over many years.

Case study: What were the effects of China's One-Child Policy?

In the 1970s, China's government feared that rapid population growth would cause shortages of food, jobs and housing. It introduced the One-Child Policy in 1979, allowing most families to have only one child. Families that broke the rule faced fines or job loss.

China's fertility rate fell from 7.5 in 1963 to 1 in 2025. Its population peaked at 1.43 billion in 2022 and has begun shrinking. By 2050, it is projected to fall to 1.31 billion.

How did the policy affect population structure?

Better access to healthcare also enabled people to live longer. The share of elderly people, described here as those above 65 years, is expected to increase from 14 per cent in 2023 to 26 per cent in 2050.

As people grow older and retire, fewer younger workers are available for farms, factories and offices. This could potentially slow the country's economic growth. The issue concerns the balance between age groups as well as the total number of people.

What were the effects on families?

A generation of children grew up without siblings and kinship networks. Kinship networks are connected social relationships formed through blood, marriage and adoption. Population policies can therefore shape family relationships as well as economic activity.

China ended the policy in 2015 and now allows up to three children. Yet fertility remains below replacement level. The continuing low fertility illustrates the policy's lasting influence on society and the economy, even after the original restriction was removed.

How do mortality and migration change population?

Death rate, or mortality rate, is the number of deaths in a population during a year, typically expressed per 1,000 people. A lower mortality rate indicates the availability of quality healthcare and better nutrition.

What do child mortality and life expectancy measure?

Child mortality measures deaths of children under five years of age per 1,000 live births. It indicates child survival and overall child health. India's child mortality fell from 271 per 1,000 in 1950 to 28 in 2023.

Life expectancy at birth is the average number of years a newborn is expected to live if present health, safety and living conditions continue. In India, it rose from 30 years at independence to 70 years in 2024.

An average of 70 does not mean every individual will live exactly 70 years. It describes the expected average under the stated conditions. Child mortality, death rate and life expectancy each reveal a different feature of people's health and survival.

Why do people migrate?

Migration is movement from one place to another, within or outside a country, to settle temporarily or permanently. People tend to move for better employment and education. Sometimes natural disasters and political instability push them to leave their homes.

Places receiving migrants see their populations rise over time. Delhi, Mumbai and Bengaluru have experienced significant population growth through migration. This is a different source of local population growth from the birth of children already living in an area's families.

Concentrating a very large population in a limited area can put pressure on water, air and land. It can also strain transport and housing. Migration therefore connects population change with the need to plan services and manage resources.

A migration study can collect a person's age, occupation, residence and length of stay, together with reasons for moving. Lack of facilities, poor infrastructure and limited jobs are among the factors that such a study can investigate.

What are the three stages of demographic transition?

Demographic transition describes changes from high birth and death rates towards low birth and death rates over time. Economic development, healthcare, education and women's increased role in household decisions influence this transition. Different combinations of births and deaths produce different patterns of population growth.

What happens at each stage?

In Stage 1, many births are accompanied by many deaths, so the population changes very slowly or remains stagnant. Poor healthcare and low literacy explain India's experience during 1901 to 1921.

In Stage 2, better healthcare reduces deaths as economies develop. Birth rates remain high, however, producing rapid population growth. The important change is that deaths decline before births have fallen in the same way.

In Stage 3, death rates remain low while births begin falling. Urbanisation, higher income, education and more women entering the workforce contribute to smaller families. Overall population growth therefore slows.

How can lower fertility eventually change the trend?

1. Access to education improves and more women participate in paid work.
2. Women are more likely to marry later and have fewer children, while urban living costs favour smaller families.
3. Lower fertility is accompanied by a lower birth rate, slowing population growth.
4. If fertility drops significantly and births fall further, population starts shrinking, as seen in countries such as Italy, Japan and South Korea.

India's fertility began to decline after the mid-1980s and is now below replacement level. Understanding the sequence helps distinguish rapid growth caused by falling deaths from slower growth caused by falling births.

How do distribution and sex ratio describe India's population?

Geographical distribution describes how people are spread across places. Population composition describes characteristics such as age, gender, occupation and education. Both are needed to understand India's diverse population and the needs of people living in different states.

How do population shares differ?

Uttar Pradesh has a 16 per cent share of India's population. Maharashtra and Bihar each have 9 per cent, and West Bengal has 8 per cent. Madhya Pradesh, Tamil Nadu and Rajasthan each have 6 per cent.

These are shares of the country's population, rather than counts of people or birth rates. A state's population share describes its part of the national total. It does not by itself describe whether its people are mainly young or elderly.

What does sex ratio tell us?

Definition: Sex ratio is the number of females per 1,000 males in a population. It is a demographic indicator used to examine the balance between females and males.

India's sex ratio improved from 933 in Census 2001 to 943 in Census 2011. Women made up 48.5 per cent of the total population in 2011. The ratio remained below 1,000, even though it had improved.

Kerala, Puducherry and Tamil Nadu had ratios above or near 1,000 in the census comparison. A balanced sex ratio is important for equitable development, meaning fair development, social stability and population growth that can be sustained.

Read the comparison base carefully: 943 means 943 females for every 1,000 males. It does not mean that women form 943 per cent of the population, or that the total population contains only 1,943 people.

How do we read and draw a population pyramid?

A population structure diagram displays a population by age and gender. It is often called a population pyramid. Younger people appear at the bottom, adults in the middle and elderly people at the top. Its shape helps show how the population is changing.

What do different shapes mean?

A wide base shows many children and a young, growing population. A widest middle indicates that most people are working adults and that the population is stable. A wide top indicates more older people than young adults and an ageing population.

Four panels are labelled 1950, 1990, 2020 and 2030. Males appear on the left and females on the right. The earlier panels are more triangular; the later panels have wider middle age groups and narrower bases relative to those middle groups.

See Fig. 6.16 in your NCERT textbook

In the 1950s, India's pyramid showed many children and fewer elderly people. Families had many children, while life expectancy was around 30 to 35 years because healthcare and nutrition were not as good.

More recently, the shape has become more bell-like. The base has narrowed as families have fewer children. The middle has widened, while the top is slowly widening as improved healthcare, nutrition and living conditions help people live longer.

How can the estimated 2021 data be plotted?

The following values are age-group-wise percentages, with separate male and female columns. The label 80+ means 80 years and above. Preserve each value when drawing the two sides of the diagram.

Arrange the age groups from youngest at the bottom to oldest at the top. Use a common percentage scale on both sides, with male bars to the left and female bars to the right. Label the age groups, units and year clearly.

What is India's demographic dividend?

Demographic dividend is the potential economic growth arising from a younger, productive age structure. A large working-age population can contribute through work, businesses and taxes. It is an opportunity to increase economic activity, rather than an automatic guarantee of prosperity.

A youth bulge means a large young population aged 16 to 30 years. It is common in Stage 2 of demographic transition. Around 27 per cent of India's population is under 15, while nearly 65 per cent is in the 15 to 59 working-age group.

How do younger age structures compare?

Median age is the age dividing a population into two equal halves, one younger and one older. The figures below compare the median ages of selected countries. They describe the middle of an age distribution, rather than life expectancy.

USA stands for United States of America. India's lower median age highlights its comparatively young population. Many young people can work in farms, factories and offices, or start businesses, increasing the volume of economic activity.

How can this opportunity support development?

Working people earn money and pay taxes, compulsory government contributions charged on incomes, business profits or some goods, services and transactions. Governments can use this revenue to build schools, hospitals, roads and parks.

Making use of the dividend requires investment in education, skills and healthcare, together with employment. These develop human capital, meaning people's capacities to contribute through their knowledge, skills and health. A young population needs opportunities to put those capacities to work.

Note: Keep age ranges attached to their particular figures. The general working-age definition uses 15 to 64 years; the nearly 65 per cent share uses 15 to 59 years. These are different age bands.

Why is India's demographic opportunity limited?

The demographic dividend lasts for a limited window. The growth in India's young population is expected to decrease beyond 2050. After 2050, the population would begin moving towards an older age structure, changing the balance between workers and people needing support.

The number of children under five peaked in 2007 and has fallen since then. The number of people under 15 peaked slightly later, in 2011, and is also declining. These changes concern particular age groups, rather than an immediate fall in total population.

How does ageing differ between states?

Population ageing means a shift towards an older population. Kerala and Tamil Nadu are experiencing significant ageing compared with Bihar and Uttar Pradesh. Different states can therefore face different needs for schools, jobs and elderly care at the same time.

State areas are shaded in different intensities of blue. The legend runs from 6.7 to 12.6 per cent. Kerala is darkly shaded. The map compares the elderly share of population, rather than each state's total number of residents.

See Fig. 6.19 in your NCERT textbook

What pressures can ageing create?

More elderly people need care, while fewer young workers are available to support them. This puts pressure on healthcare facilities. When retiring workers have fewer replacements, economic growth can slow. Fewer young taxpayers also make it harder to fund services.

A pension is a regular payment by the state to people at or above the official retirement age. Funding pensions is one of the challenges governments face as the age structure changes.

Elderly people also contribute knowledge, wisdom and guidance to families and society. Storytelling and participation in rituals help maintain cultural continuity. Some knowledge held by older people may not be recorded in books, so their contribution extends beyond paid employment.

Case study: How can Japan and other countries respond to ageing?

Japan illustrates the challenges of an ageing population. It has a median age of 50 years, and its population is shrinking. Countries facing ageing need to support older people while maintaining their ability to produce goods and services and develop new ideas.

What measures has Japan taken?

Japan has raised the retirement age and used automation, technology that performs tasks automatically, to compensate for labour shortages. It has large-scale community centres, robots and artificial intelligence assistants, computer systems that perform tasks requiring aspects of human intelligence, to help care for older adults.

Productivity measures the amount of goods and services produced using a given quantity of resources. Maintaining productivity matters when there are fewer workers to replace those retiring. Technology is one response to this pressure on the workforce.

How can developing countries prepare?

Developing countries need to invest in good education, skills and healthcare to use their demographic dividend. Preparing for ageing and making the most of a younger population are connected responsibilities, because the age structure changes over time.

As more women take formal jobs, they often experience a double burden: paid job responsibilities alongside household duties. Lack of childcare, joint-family support and flexible working hours can make participation in work difficult.

Supportive families and childcare facilities such as daycare centres can help turn the demographic dividend into lasting progress. Policies in many nations have tried to revive fertility, but they have not been very successful so far.

Population planning therefore involves education, employment, healthcare, family support and care for older people together. The needs of children, workers and elderly people differ, so understanding the population's composition helps countries decide which services and opportunities to develop.

Glossary

• Demography — The study of human population size, composition and changes caused by births, deaths and migration.
• Census — The collection, compilation, analysis and sharing of information about all people in a defined area at a specific time.
• Population composition — The characteristics making up a population, including age, gender, education, occupation and religion.
• Birth rate — Live births during a specified period, usually measured per 1,000 people in one year.
• Fertility rate — The average number of children a woman is likely to have during her lifetime.
• Replacement level fertility — The fertility level needed to replace parents in the population, often represented by 2.1 children per woman.
• Death rate — Deaths in a population during a year, typically expressed per 1,000 people.
• Child mortality — Deaths of children under five years of age per 1,000 live births.
• Life expectancy — The average years a newborn is expected to live if present health, safety and living conditions continue.
• Migration — Movement within or across countries to settle temporarily or permanently in a new place.
• Demographic transition — Changes in population patterns as high birth and death rates give way to lower rates.
• Sex ratio — The number of females per 1,000 males, used to examine population gender balance.
• Population pyramid — A graph showing population by age and gender, with younger groups below older groups.
• Youth bulge — A large young population aged 16 to 30, common in Stage 2 of demographic transition.
• Demographic dividend — The economic growth potential arising from a country's younger and productive population structure.

Common errors and misconceptions

• Misconception: Demography is just counting people. Correct: It also studies population composition and changes through births, deaths and migration.
• Misconception: Birth rate and fertility rate mean the same thing. Correct: Birth rate usually measures annual births per 1,000 people; fertility rate measures average lifetime children per woman.
• Misconception: Fertility below 2.1 means population immediately shrinks. Correct: Population might shrink over time; India's population still grows despite below-replacement fertility.
• Misconception: Life expectancy of 70 means everyone dies at 70. Correct: It is an expected average under specified living conditions, not an individual's fixed lifespan.
• Misconception: A sex ratio of 943 means 943 females per 1,000 people. Correct: It means 943 females per 1,000 males.
• Misconception: Child mortality uses the same base as the general death rate. Correct: Child mortality concerns under-five deaths per 1,000 live births; the general death rate uses the population.
• Misconception: A large young population guarantees economic growth. Correct: The demographic dividend is potential that requires education, skills, healthcare and employment opportunities.
• Misconception: Older people have no role after retirement. Correct: They share knowledge, wisdom and cultural guidance with families and society.

Exam-style questions with model answers

Q1. Distinguish between birth rate and fertility rate. [2 marks]

1. Birth rate usually measures the number of live births per 1,000 people in a year.
2. Fertility rate measures the average number of children a woman is likely to have during her lifetime.

Q2. Explain three ways demographic information helps governments and businesses plan. [3 marks]

1. Information about age structure helps governments plan services: a population with many children needs more schools, while a larger elderly share needs more healthcare facilities.
2. A higher proportion of young working-age people signals a greater need to generate jobs, helping governments plan opportunities for people to earn a living.
3. Businesses use characteristics such as customers' age, gender and income to create products suited to people's needs and to assess potential demand.

Q3. Explain the three stages of demographic transition, referring to the combination of birth and death rates in each. [3 marks]

1. In Stage 1, birth and death rates are both high, leaving population growth very slow or stagnant because high births are accompanied by high deaths.
2. In Stage 2, better healthcare lowers death rates while birth rates remain high. The resulting combination causes rapid growth in the population.
3. In Stage 3, death rates remain low and birth rates fall as education, income, urbanisation and women's employment increase. Population growth slows, and sufficiently low fertility can lead to shrinkage.

Q4. Bihar has fertility of 3.0 and female literacy of 55%; Delhi has fertility of 1.6 and female literacy of 83.7%. Compare the two indicators, then explain two reasons families may have fewer children. [4 marks]

1. Bihar's fertility rate of 3.0 is higher than Delhi's rate of 1.6, indicating a higher average number of children per woman in Bihar.
2. Delhi's female literacy rate of 83.7 per cent is higher than Bihar's 55 per cent, showing a higher literate share in the given female populations.
3. Better education and formal employment make women more likely to marry later and have fewer children, contributing to lower fertility.
4. Rapid urbanisation brings higher living costs, particularly in cities, encouraging people to prefer smaller families and fewer children.

Q5. China's population peaked at 1.43 billion in 2022 and is projected at 1.31 billion in 2050. Its share of people above 65 is expected to rise from 14% in 2023 to 26% in 2050. State the two trends and explain three challenges they could create. [5 marks]

1. The population is projected to shrink from the 2022 peak of 1.43 billion to 1.31 billion in 2050. The later figure describes an expected future total.
2. The share of people above 65 is expected to rise from 14 per cent to 26 per cent, indicating a shift towards an older population.
3. As more people retire, fewer younger workers are available to replace them in farms, factories and offices. This could potentially slow economic growth.
4. More elderly people require care and healthcare facilities, increasing the pressure on systems that provide medical services and support for older adults.
5. With fewer young taxpayers, governments face greater difficulty paying pensions and providing services, because the needs of an ageing population must still be supported.

Q6. Define demographic dividend and explain five ways India can turn this opportunity into lasting progress. [6 marks]

1. Demographic dividend is the economic growth potential created by a younger, productive age structure, with many people able to contribute through employment and enterprise.
2. Investment in good education helps young people develop the knowledge needed to contribute to economic activity and make use of available opportunities.
3. Training and skill development prepare people to participate productively in work, helping the large working-age population contribute to the country's growth.
4. Investment in healthcare supports people's health, which is needed alongside education and skills to make effective use of a younger population.
5. Employment opportunities allow young people to work in farms, factories and offices, while opportunities to start businesses can expand the volume of economic activity.
6. Supportive families, childcare facilities and flexible working arrangements help women manage employment alongside household responsibilities, enabling wider participation in the workforce.

Q7. India's sex ratio rose from 933 females per 1,000 males in 2001 to 943 in 2011. State what changed and whether the 2011 ratio reached 1,000 females per 1,000 males. [2 marks]

1. The number of females relative to every 1,000 males increased, showing an improvement in the sex ratio.
2. The 2011 ratio remained below 1,000, since there were 943 females for every 1,000 males.

Q8. Explain four links between migration, population growth and the needs of receiving cities. [4 marks]

1. People tend to move to cities seeking better employment and educational opportunities, while natural disasters or political instability can sometimes push them from their original homes.
2. An influx of migrants increases the population of receiving places over time, adding people through movement rather than through local births alone.
3. A very large population concentrated in a limited area can put pressure on resources such as water, air and land.
4. Growing population can strain housing and transport services, making the planning of facilities and the management of resources important for receiving cities.

Key takeaways

• Demography studies population size, composition and change, helping governments plan services and businesses understand people's needs.
• Births, deaths and migration shape population change; fertility concerns the average number of children per woman.
• Fertility below replacement level means population might shrink over time, rather than guaranteeing an immediate decline.
• Demographic transition moves from high birth and death rates towards low rates, changing the pace of population growth.
• Population pyramids display age and gender composition, revealing whether younger, working-age or older groups are prominent.
• India's demographic dividend offers growth potential through a large productive population, supported by education, skills, healthcare and employment.
• The opportunity is limited because India's population would begin moving towards an older age structure after 2050.
• Ageing increases care and pension needs, while older people continue contributing knowledge, wisdom and cultural guidance.

Test yourself

What information does population composition describe?

It describes characteristics such as age, gender, education, occupation and religion within a population.

How often is India's census generally conducted?

It is generally conducted every 10 years to assess population size and characteristics.

What is a population projection?

It is an estimate of a future population situation based on the study of present trends.

What does child mortality measure?

It measures deaths of children under five years of age per 1,000 live births.

Why can population grow rapidly in Stage 2?

Death rates fall with better healthcare while birth rates remain high, causing rapid population growth.

What does a wide middle in a population pyramid indicate?

It indicates that most people are working adults and that the population is stable.

What is the double burden often faced by working women?

It is the combination of paid job responsibilities and household duties, made harder by inadequate childcare and support.

How can older people contribute beyond paid work?

They share knowledge and wisdom, guide families and maintain cultural continuity through storytelling and rituals.