1. Chapter at a Glance
People differ in age, gender, education, occupation and religion, and populations keep changing through births, deaths and migration. Demography is the study of these features and changes. It helps governments plan schools, hospitals, housing, water and jobs, and helps businesses understand customers. This chapter covers population trends in India and the world, key indicators (birth rate, fertility, death rate, migration), the demographic transition, India's population structure and sex ratio, population pyramids, and India's limited window for a demographic dividend.
- What is demography, and what are its key concepts?
- How has the population of India and the world changed?
- How do population trends shape societies and economies?
2. Population at a Glance
- India's census, the official count of everyone with details of age, sex, education, language, religion, occupation and more, is generally held every 10 years; the last completed census was in 2011.
- In 2023 India overtook China as the world's most populous country (UN estimates); Indians are about one-sixth (roughly 17–18%) of humanity.
- World population: 2.5 billion (1950) → about 8.2 billion (2025) → about 9.7 billion (2050), with UN projections of a peak around 10.3 billion in the mid-2080s, then a slow decline.
- Rapid growth after 1950 came from antibiotics, vaccines, oral rehydration, clean water and sanitation, and rising prosperity — fewer deaths, especially of children.
- China, Japan and Italy are already shrinking; India is still growing; countries like Nigeria and Ethiopia are growing fast. Asia holds most of the world's people (about 4.8 billion), followed by Africa (about 1.5 billion).
3. What Determines a Country's Population?
| Indicator | Meaning |
|---|---|
| Birth rate | Live births per 1,000 people in a year |
| Fertility rate (Total Fertility Rate) | Average number of children a woman has in her lifetime |
| Death (mortality) rate | Deaths per 1,000 people in a year |
| Migration | Movement of people within or between countries |
- Replacement-level fertility = 2.1: two children replace the parents, and the extra 0.1 allows for children who die young and for slightly more boys than girls being born. Above 2.1 the population tends to grow; below it, it eventually shrinks.
- India's fertility fell from about 5.7 in 1950 to around 2.0 (NFHS-5, 2019–21) — now below replacement. Campaigns like “Hum do, hamare do” promoted small families. It still varies by State (NFHS-5): Bihar 3.0, Uttar Pradesh 2.4, Jharkhand 2.3, Karnataka 1.7, Punjab 1.6, Delhi 1.6.
- Why fertility falls: girls' education, women in formal jobs, later marriage, urbanisation and high living costs.
- China's One-Child Policy (1979/80–2015) pushed fertility far below replacement; China's population peaked around 2022 and is now falling while the share of elderly rises fast — fewer workers support more retirees, and a whole generation grew up without siblings.
- Death rate and life expectancy: India's under-5 child mortality fell from roughly 271 per 1,000 births in 1950 to about 28 in 2023; life expectancy rose from about 30–32 years at Independence to about 70 now. Life expectancy is the average years a newborn can expect to live under present conditions.
- Migration for jobs and education swells cities like Delhi, Mumbai and Bengaluru, straining water, housing and transport, while villages may be left with the old and very young.
4. The Demographic Transition
| Stage | Birth rate | Death rate | Growth | India |
|---|---|---|---|---|
| 1 | High | High | Slow / stagnant | 1901–1921 (poor healthcare, famines, epidemics) |
| 2 | High | Falling | Rapid | After 1951 |
| 3 | Falling | Low | Slowing; may later shrink | Fertility falling since the mid-1980s, now below replacement |
Countries such as Italy, Japan and South Korea have gone further — births below deaths, so populations are shrinking.
5. India's Population Structure
- Population is unevenly spread: Uttar Pradesh has the largest share, followed by Maharashtra and Bihar; many northeastern and small States/UTs hold under 1% each.
- Sex ratio = number of females per 1,000 males: 933 (2001) → 943 (2011), when women were about 48.5% of the population. Kerala and Puducherry had more females than males (Tamil Nadu was close to 1,000) — reflecting better women's health, education and longer female life expectancy.
- A population pyramid shows males and females in each age group: a wide base = many children (young, growing population, e.g. Nigeria); a wide middle = many working adults; a wide top = an ageing population (e.g. Japan).
- India's pyramid has changed from a sharp triangle in the 1950s to a bell shape today — a narrower base (fewer births), a broad middle (working age) and a slowly widening top (longer lives).
6. India's Demographic Dividend — a Limited Window
- Roughly a quarter of Indians are under 15 and about two-thirds are of working age, and India's median age is much lower than Japan's, Italy's, Germany's or China's.
- A large, young working population can produce, earn and pay taxes that fund schools, hospitals and roads — the demographic dividend. A big group aged 16–30 is called a youth bulge.
- The window is limited: the number of children under five peaked around 2007 and under-15s around 2011; after about 2050 India will age. Kerala and Tamil Nadu already have a much higher share of elderly than Bihar or Uttar Pradesh.
- Ageing means more health-care needs, more pensions and fewer young taxpayers. Japan has responded with later retirement, automation and care robots.
- To cash the dividend India must invest in education, skills and health, create jobs, and support working women (who often face a double burden of job and housework) with childcare and flexible work.
- India's tradition of āshrama dharma (brahmacharya, gṛihastha, vānaprastha, sannyāsa) reminds us that older people stay valuable as guides, storytellers and keepers of knowledge.
7. Master Table: Key Terms and Formulas
| Term | Meaning / formula |
|---|---|
| Demography | Study of population size, structure and change |
| Birth rate | (Live births ÷ population) × 1,000 |
| Death rate | (Deaths ÷ population) × 1,000 |
| Natural growth rate | Birth rate − death rate |
| Replacement fertility | 2.1 children per woman |
| Sex ratio | (Females ÷ males) × 1,000 |
| Child mortality | Deaths under 5 per 1,000 live births |
| Working-age population | Generally ages 15–64 (15–59 in Indian usage) |
| Demographic dividend | Growth potential from a young working population |
| Projection | Forecast based on present trends |
8. Master Summary Table
| Indicator | Then | Recent |
|---|---|---|
| Fertility rate (India) | ~5.7 (1950) | ~2.0 (NFHS-5) |
| Life expectancy (India) | ~30–32 (1947) | ~70 |
| Under-5 mortality (India) | ~271 per 1,000 (1950) | ~28 (2023) |
| Sex ratio (India) | 933 (2001) | 943 (2011) |
| World population | 2.5 billion (1950) | ~8.2 billion (2025) |
Chart — world population (billions; UN figures and projections):
9. Mind Map
- Size, structure
- Census
- Birth, fertility (2.1)
- Death, migration
- 3 stages
- China, Japan examples
- Sex ratio 943
- Pyramid → bell
- Young workforce
- Window till ~2050
10. Tips and Tricks
- Replacement “2 + 0.1”: 2 to replace parents, 0.1 for child deaths and sex imbalance at birth.
- Pyramid shapes: Triangle = young, Bell = balanced, Inverted/urn = ageing.
- Sex ratio rose by 10 from 2001 to 2011: 933 → 943.
- Birth rate (per 1,000 people) is not the same as fertility rate (children per woman).
- A falling fertility rate does not mean the population falls immediately — it keeps growing for years because many young people are still entering parenthood.
11. Important One-liners
- Demography is the study of human populations.
- India became the most populous country in 2023.
- Replacement-level fertility is 2.1.
- India's fertility rate is now below replacement.
- China's One-Child Policy ended in 2015.
- India's sex ratio was 943 in 2011.
- Kerala has more females than males.
- Life expectancy in India is now about 70 years.
- Migration has swelled cities like Delhi and Mumbai.
- India's pyramid is now bell-shaped.
- India's demographic dividend window lasts till around 2050.
12. Exam-pattern Questions with Detailed Answers
What is the replacement-level fertility rate?
- 1.5
- 2.0
- 2.1
- 3.0
Show answer
2.1 children per woman keeps population stable over time.
Answer: (C)
India's sex ratio in Census 2011 was:
- 933
- 940
- 943
- 1,000
Show answer
943 females per 1,000 males, up from 933 in 2001.
Answer: (C)
Why does a government study demography?
Show answer
To plan schools for children, hospitals and pensions for the elderly, jobs for the working-age, and housing, water and transport for growing areas — allocating resources where they are needed.
Answer: For planning services and resources
Why has India's fertility rate fallen?
Show answer
More education for girls, women in jobs, later marriage, better child survival (so families need fewer births), urbanisation and higher living costs, and family-planning awareness.
Answer: Education, work, health, urban costs
Describe the three stages of demographic transition.
Show answer
Stage 1: high births and high deaths — slow growth. Stage 2: deaths fall with better healthcare while births stay high — rapid growth. Stage 3: births fall too, deaths stay low — growth slows and may turn negative.
Answer: As above
What does a population pyramid with a wide base tell us?
Show answer
Many children are being born — a young, fast-growing population needing schools, child health care and, later, many jobs (e.g. Nigeria; India in the 1950s).
Answer: Young, growing population
What happens to a village when many young people migrate to cities?
Show answer
Farms may lack workers; the elderly and children are left behind; remittances may raise incomes; some houses and fields lie unused; in cities, crowding strains housing, water and transport.
Answer: Labour shortage and ageing at home, crowding in cities
Is a high birth rate always good for a country?
Show answer
Not always. It can supply future workers, but if schooling, health and jobs don't keep pace it brings unemployment, poverty and pressure on land and water. Very low birth rates are also a problem (ageing, labour shortage). A balanced rate with investment in people is best.
Answer: No — balance and investment matter
What lessons does China's One-Child Policy offer?
Show answer
Forced, sudden cuts in births produce rapid ageing, a shrinking workforce, pension pressure, gender imbalance and loss of family networks; even after relaxing rules (three children allowed), fertility stays low. Population policy should rely on education, health and choice, and plan for long-term effects.
Answer: Coercive limits have lasting side-effects
What should India do now to make the most of its demographic dividend?
Show answer
Improve school and higher-education quality and vocational skills; create jobs in manufacturing and services; strengthen health and nutrition; support women's workforce participation with childcare and safety; encourage entrepreneurship; and prepare pensions and elderly care for the ageing that follows after 2050.
Answer: Invest in skills, jobs, health, women; plan for ageing
Why are Kerala and Tamil Nadu ageing faster than Bihar and Uttar Pradesh?
Show answer
They reached high literacy, especially among women, good health care and low fertility decades earlier, and people live longer, so the share of elderly is larger. Bihar and UP still have higher fertility and younger populations, so they are at an earlier stage of transition.
Answer: Earlier fertility decline and longer life expectancy
13. Quick Revision Summary
- Demography = size, structure, change; census every 10 years (last completed 2011).
- World 2.5 → 8.2 billion (1950–2025); India most populous since 2023.
- Indicators: birth rate, fertility (replacement 2.1; India ~2.0), death rate, migration.
- Transition: 3 stages; China's one-child policy; ageing East Asia and Europe.
- Sex ratio 933 → 943; pyramid from triangle to bell.
- Demographic dividend till ~2050: invest in education, skills, health, jobs and women.