What is demography?
How many schools and hospitals are needed? The government must know how many people live there and of what ages.
Demography is the study of the size, structure and changes over time of the human population.
Key idea 1: Size, structure and trend — A population differs by age, gender, education, occupation and religion, and changes through births, deaths and migration. Population structure shows how it is made up by age, gender and so on. The working-age population is 15 to 64 years.
- Easy: The census is generally held every 10 years.
- Medium: Working-age is 15–64 years.
- Exam-type: If children are many, what is needed? — More schools.
In the figure: Size, structure and trend together give the picture.
Key idea 2: Uses and the census — Governments use it to plan schools, hospitals, roads, housing, water, energy and waste management. Many children mean more schools; many elderly mean more healthcare; many young workers mean more jobs. Businesses use it to understand customers. In India the census is generally held every 10 years.
Studying population helps allocate resources well.
Thinking population means only the total. Structure matters too.
Three words: size, structure, trend. Memory clue: S-S-T.
Spot the difference
| Point | Size | Structure |
|---|---|---|
| Meaning | Total people | Age, gender, education etc. |
| Use | Total resources | Schools, hospitals, jobs |
Practice questions
- 1What is demography?
- 2How often is the census held?
- 3What is the working-age group?
- 4What changes population?
- 5How does the government use it?
- 6If the elderly are many, what is needed?
- 7Why do businesses need it?
- 8What challenge comes with many young workers?
Show answers (try them yourself first)
- 1Study of population size, structure and change.
- 2Generally every 10 years.
- 315–64 years.
- 4Births, deaths and migration.
- 5To plan schools, hospitals, roads, water, etc.
- 6More healthcare facilities.
- 7To know customers’ age, gender and income and make suitable products.
- 8Creating enough jobs for them.
Population of the world and India at a glance
Has your town become more crowded? The world’s population has almost tripled in 75 years.
A projection is an estimate of a future situation based on present trends.
Key idea 1: World population — 2.5 billion in 1950, 8.2 billion in 2025 and expected to reach 9.7 billion by 2050. UN projections say it will peak at 10.3 billion by the mid-2080s and then decline. Growth sped up after 1950 as antibiotics, vaccines, ORS and better water and sanitation reduced child deaths. China, Japan and Italy are shrinking; Nigeria and Ethiopia are growing fast.
- Easy: World population is 8.2 billion in 2025.
- Medium: India became the most populous in 2023.
- Exam-type: Why fast growth after 1950? — Better health care, vaccines and sanitation.
In the figure: Population will grow to a peak and then fall.
Key idea 2: India — In 2023 India overtook China to become the most populous country; about 17 per cent of the world’s people are Indians. It is still growing, though it will begin to fall in the coming decades.
Population growth has slowed.
Thinking all countries are growing. Some are shrinking.
2.5 → 8.2 → 9.7 (billion). Memory clue: 1950 / 2025 / 2050.
Spot the difference
| Country | Trend | Example |
|---|---|---|
| India | Growing for now | Most populous from 2023 |
| China, Japan, Italy | Shrinking | Low births |
| Nigeria, Ethiopia | Fast growth | Africa |
Practice questions
- 1World population in 2025?
- 2Expected by 2050?
- 3When did India become the most populous country?
- 4India’s share of world population?
- 5Why was growth fast after 1950?
- 6Two shrinking countries?
- 7When and how high is the peak?
- 8Why may projections not be exact?
Show answers (try them yourself first)
- 18.2 billion.
- 29.7 billion.
- 32023.
- 4About 17 per cent.
- 5Better health, vaccines, water and sanitation; fewer child deaths.
- 6Japan and China (and Italy).
- 7About 10.3 billion by the mid-2080s.
- 8They rest on present trends; if trends change, results change.
What decides population: births, deaths, fertility, migration
Did your grandparents have five or six siblings? Families are smaller now, and the change shows in national numbers.
The fertility rate is the average number of children a woman has in her lifetime; the birth rate is live births per 1,000 people in a year.
Key idea 1: Four factors — Population depends on births, deaths and migration. A fertility rate of 2.1 is the ‘replacement level’: above it population grows, below it it may shrink. Lower death rates show better healthcare and nutrition. In India child mortality fell from 271 per 1,000 in 1950 to 28 in 2023; life expectancy rose from about 30 years at independence to 70 in 2024. Migration happens for jobs, education or disasters; Delhi, Mumbai and Bengaluru grew through it.
- Easy: 2.1 is the replacement fertility rate.
- Medium: India’s life expectancy rose from 30 to 70 years.
- Exam-type: Effect of women’s education on fertility? — It falls: later marriage and fewer children.
In the figure: Births and in-migration add; deaths reduce.
Key idea 2: China’s and India’s efforts — China introduced the One-Child Policy in 1979; its fertility rate went from 7.5 in 1963 to 1 in 2025. China’s population peaked at 1.43 billion in 2022 and began to shrink; the elderly share is expected to rise from 14 per cent in 2023 to 26 per cent in 2050. The policy ended in 2015. India ran ‘Hum do hamare do’ from 1952; its fertility rate fell from 5.7 in 1950 to 1.9 in 2025. Education (especially of girls), jobs and urbanisation lowered it.
If fertility falls below 2.1 the population may shrink over time.
Treating birth rate and fertility rate as same. Birth rate is per 1,000 people; fertility rate is per woman.
Fertility 2.1 = replacement. Memory clue: 2 parents + a little extra (0.1) = 2.1.
Spot the difference
| Rate | Meaning | Example |
|---|---|---|
| Birth rate | Births per 1,000 | — |
| Fertility rate | Children per woman | India 1.9 (2025) |
| Death rate | Deaths per 1,000 | Child deaths 271 → 28 |
Practice questions
- 1What is the replacement fertility rate?
- 2How far did child mortality fall in India?
- 3What is life expectancy?
- 4When was China’s One-Child Policy?
- 5Since when ‘Hum do hamare do’?
- 6Two reasons for migration?
- 7Why is fertility falling?
- 8What was the long-term effect of China’s policy?
Show answers (try them yourself first)
- 12.1.
- 2From 271 in 1950 to 28 in 2023 per 1,000.
- 3The average years a newborn is expected to live.
- 41979 (ended 2015).
- 5From 1952.
- 6Jobs and education (or disasters).
- 7Girls’ education, women in jobs, later marriage, urbanisation and cost of living.
- 8Population began to shrink, the elderly share grew, a generation without siblings arose; fertility stayed low after the policy ended.
Demographic transition: three stages
As a person goes through childhood, youth and old age, so does a country’s population.
Demographic transition is the move from high birth and death rates to low birth and death rates.
Key idea 1: Stages 1 and 2 — Stage 1: high births and high deaths; slow growth. India in 1901–1921 (poor healthcare, low literacy). Stage 2: better healthcare lowers deaths while births stay high; rapid growth. India after 1951.
- Easy: India was in Stage 2 after 1951.
- Medium: In Stage 3 the birth rate falls.
- Exam-type: Why fast growth in Stage 2? — Deaths fall but births stay high.
In the figure: Each stage has a different mix of birth and death rates.
Key idea 2: Stage 3 — Stage 3: deaths stay low and births begin to fall (urbanisation, income, education, women in the workforce). If births fall very low the population shrinks, as in Italy, Japan and South Korea. In India fertility began to decline after the mid-1980s and is now below replacement level.
As health improves, the death rate falls first; the birth rate later.
Thinking birth rate falls in Stage 2. It is still high.
1: both high; 2: death falls; 3: birth falls. Memory clue: First death falls, then birth.
Spot the difference
| Stage | Birth rate | Death rate |
|---|---|---|
| 1 | High | High |
| 2 | High | Falling |
| 3 | Falling | Low |
Practice questions
- 1Birth and death rates in Stage 1?
- 2When was India in Stage 1?
- 3What marks Stage 2?
- 4When was Stage 2 in India?
- 5Why does birth rate fall in Stage 3?
- 6Examples of Stage 3 countries?
- 7When did India’s fertility begin to fall?
- 8What causes demographic transition?
Show answers (try them yourself first)
- 1Both high.
- 21901–1921.
- 3Death rate falls, births high; rapid growth.
- 4After 1951.
- 5Because of urbanisation, income, education and more women working.
- 6Italy, Japan, South Korea.
- 7After the mid-1980s.
- 8Economic development, healthcare, education and women’s role in household decisions.
India’s population composition and the demographic dividend
Which age group is biggest in your class? A country’s pyramid shows its share of children, workers and elderly.
The demographic dividend is the growth potential a country gets from a young, working-age population.
Key idea 1: Sex ratio and states — The sex ratio is females per 1,000 males. India’s was 933 in 2001 and 943 in 2011. Kerala, Puducherry and Tamil Nadu are near or above 1,000. Uttar Pradesh has the largest share (about 16 per cent), followed by Maharashtra and Bihar (about 9 per cent each).
- Easy: India’s median age is 28 years.
- Medium: A wide base means many children.
- Exam-type: How long does the dividend last? — A limited window; it fades after 2050.
In the figure: The shape of the pyramid tells the age story of a country.
Key idea 2: Population pyramid — A pyramid shows population by age and gender. A wide base = many children (young, growing, like India or Nigeria); a wide middle = stable; a wide top = many elderly (Japan). In 1950 India’s was a narrow triangle with life expectancy of 30–35 years. Now it is bell-shaped: narrower base and a wide working-age middle.
Key idea 3: Dividend and ageing — About 27 per cent of Indians are under 15 and nearly 65 per cent are of working age (15–59). Median age: India 28, Japan 50, Italy 48, Germany 47, China 40, USA 39. Young people work and pay taxes, from which the government builds schools and hospitals; the window is limited because after 2050 the young population falls and India begins to age. Kerala and Tamil Nadu already show ageing. Japan raised its retirement age and uses technology and robots. Developing countries must invest in education, skills and healthcare and provide childcare.
The dividend pays only if the young get education and jobs.
Thinking many young people automatically means growth. Investment in education, skills and health is needed.
India 28; Japan 50. Memory clue: Young India = base + middle; old Japan = top.
Spot the difference
| Point | Young (e.g. India) | Ageing (e.g. Japan) |
|---|---|---|
| Pyramid | Wide base/middle | Wide top |
| Median age | 28 | 50 |
| Challenge | Jobs, skills | Healthcare, pensions, labour shortage |
Practice questions
- 1What is the sex ratio?
- 2India’s sex ratio in 2011?
- 3Which state has the largest population share?
- 4What does a wide-base pyramid show?
- 5What is the demographic dividend?
- 6Why is this a limited window?
- 7Problems of an ageing population?
- 8What has Japan done about ageing?
Show answers (try them yourself first)
- 1Females per 1,000 males.
- 2943.
- 3Uttar Pradesh (about 16 per cent).
- 4Many children; a young, growing population.
- 5Growth potential from a large working-age population.
- 6After 2050 the young population falls and the country ages.
- 7Pressure on healthcare, fewer workers, difficulty paying pensions.
- 8Raised the retirement age, used technology and robots, built community centres.
India’s population composition and the demographic dividend
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