Maarg Manthan · Topic 17.4

Population Change and Demographic Transition

Geography › Human Geography and Population · Topic 17.4

Population change is the result of births, deaths and migration. The demographic transition model describes how a society moves from high birth and death rates, through falling death rates and rapid growth, to low birth and death rates and slow or negative growth, as it develops. World population passed 8 billion in 2022. India, whose total fertility rate is now below the replacement level of about 2.1, is in the late stage of the transition.

6 min read · UPSC Prelims · Geography · Human Geography and Population

At a Glance

Components Births, deaths, migration
Stages High stationary, early expanding, late expanding, low stationary
Replacement Total fertility rate of about 2.1
World 8 billion in November 2022
India’s TFR About 2.0 (NFHS-5), 1.9 (UN estimate)
Exam link UPSC Prelims, Geography: Human Geography and Population

Where Does It Fit?

This is the fourth topic of the macro on human geography and population. The previous topic showed where people live, and this one explains how their numbers change and why. The next topic describes the composition of population by sex, age and occupation. Previous topic: Distribution and Density of Population. Next topic: Population Composition – Sex, Age and Occupation.

What Are the Components of Population Change?

In short: a population grows when births and in-migration exceed deaths and out-migration.

Natural growth: births minus deaths. Actual growth: births minus deaths plus in-migrants minus out-migrants.
Crude birth rate (CBR): live births per thousand people in a year. Crude death rate (CDR): deaths per thousand people in a year. The difference is the rate of natural increase.
Total fertility rate (TFR): the average number of children a woman would have in her lifetime at current rates. A TFR of about 2.1 is the replacement level, at which a population just replaces itself.
Migration: movement from a place of origin to a place of destination, as in Migration – Streams and Causes.

The long-term trend is dramatic. The world had about 5 million people in 10,000 BC and 500 million by 1650; it reached 1 billion in 1804, 2 billion in 1927, 4 billion in 1974 and 8 billion in November 2022. The doubling time fell from 1,500 years to 123 years and then to 47 years, and the Industrial Revolution and advances in medicine and sanitation cut the death rate and began the explosion. The United Nations projects that the world population will peak at around 10.3 billion in the 2080s and then slowly decline.

What Is the Demographic Transition Model?

Stage	Birth rate	Death rate	Growth and features
1: High stationary	High	High	Slow growth; high birth rates offset by high deaths from famine, disease and war; farming societies; India up to about 1921
2: Early expanding	High	Falling	Rapid growth; better food, sanitation and health care cut deaths but births stay high; India from about 1921 to 1951 and the decades after, and much of sub-Saharan Africa today
3: Late expanding	Falling	Low	Growth slows as urbanisation, education and the use of contraception lower fertility; many developing countries today, including India and Brazil
4: Low stationary	Low	Low	Slow or zero growth, an urban industrial society with small families; most of Europe, North America and East Asia
5: Declining (suggested)	Very low	Low to rising	Deaths exceed births; the population shrinks and ages; Japan, South Korea, Italy and China

Western Europe took about two centuries to complete the transition, whereas the developing countries have moved much faster because medical technology was imported, so their death rates fell abruptly while their birth rates remained high for a time, producing a fast rise in numbers and a large young population. The model is a generalisation, since not all societies follow the same sequence, and migration and policy can alter it.

Where Does India Stand?

History: in the decade 1901 to 1911 the birth rate was about 49 and the death rate about 43 per thousand, with natural increase of only 6.6 per thousand; the death rate then fell steadily to about 7 per thousand in 2001 to 2011, while the birth rate fell more slowly from about 41 in 1961 to about 22, so that natural increase peaked at about 22 per thousand in the 1960s and 1970s and then declined to about 15.
Fertility: India’s TFR fell to about 2.0 in the National Family Health Survey of 2019–21, below the replacement level, and the United Nations population fund estimated 1.9 in 2025. Bihar, Meghalaya and Uttar Pradesh still have higher rates, while Kerala, Tamil Nadu, Delhi and others are below 2, as in India Census 2011 – Key Population Patterns.
Population momentum: because of the large cohort of young people who are entering childbearing age, India’s population will continue to grow for a few decades even with low fertility. The UN projects a peak of around 1.7 billion in the 2060s, and the country has been the most populous since 2023.
Policy: from the first family planning programme in 1952, India moved to a target-free approach based on health and education. Census 2027, with houselisting in 2026 and enumeration in February 2027, will provide the first full count in 16 years.

The transition brings an opportunity and a challenge. The demographic dividend arises when the share of the working-age population is high and the dependency ratio low, but it can be realised only through jobs, skills and health, as in Population Composition – Sex, Age and Occupation. The risk is a later ageing of society, as seen in Japan and South Korea, where a very low fertility rate, below 1 in South Korea, is shrinking the working-age population. As an analytical point, India’s southern states are already close to the ageing stage, whereas the northern states are still young, and so the question of fiscal transfers and of seats in Parliament based on population is bound up with the demographic transition.

Why Is This Topic Important?

Model Stages asked
Link Demographic dividend
Current affairs Fertility and Census 2027

What Came Next?

The next topic describes the composition of the population by sex, age and occupation. Next topic: Population Composition – Sex, Age and Occupation.

Key People and Terms

CBR Crude birth rate
CDR Crude death rate
TFR Total fertility rate
Replacement level Fertility of about 2.1
Population momentum Growth due to a young age structure
Demographic dividend Gain from a large working-age share

Exam Corner

Points to Remember

Natural growth = births minus deaths.
Replacement TFR is about 2.1.
World reached 8 billion in 2022.
India is in the late expanding stage.
India’s TFR is about 2.0 or less.

Do Not Confuse With

Natural growth and actual growth Without versus with migration
CBR and TFR Per thousand people versus per woman
Stage 2 and stage 3 Death rate falling versus birth rate falling

Memory Hook

Death falls first, birth falls later: the gap is the explosion; then both are low and the numbers stop.

Mains Angle

Questions apply the model to India. These points add depth.

Model Four or five stages
India Late expanding, below replacement
Policy Dividend and ageing

A Question You May Face

An original practice question, not a past paper question.

“Explain the demographic transition model and discuss the stage of the transition at which India stands and its policy implications.”

How to Answer

Components Births, deaths, migration.
Model Stages.
India Late expanding.
Policy Dividend and ageing.

GS Relevance

Prelims: components of change, stages of the transition, India's stage, fertility terms. GS Paper 1: population; GS Paper 2 and 3: demographic dividend and ageing.

Frequently Asked Questions

What is the demographic transition model?

The demographic transition model describes the change of a population from high birth and death rates, through falling death rates and rapid growth, to low birth and death rates and slow or zero growth, as a society develops. It has four stages, sometimes five, and is based on the experience of Western Europe.

What are the components of population change?

Population change has three components: births, deaths and migration. Natural growth is births minus deaths, and actual growth also includes in-migration minus out-migration. Birth and death rates are measured per thousand people, and migration depends on push and pull factors.

What is the total fertility rate and the replacement level?

The total fertility rate is the average number of children a woman would have in her lifetime if current age-specific birth rates continued. The replacement level is a rate of about 2.1 children per woman, at which a population exactly replaces itself over the generations.

At what stage of the demographic transition is India?

India is in the late expanding third stage, in which the death rate is low and the birth rate has fallen considerably. Its total fertility rate is about 2.0 or less, below the replacement level, but population will keep growing for some decades because of its large young population.

What is the demographic dividend?

The demographic dividend is the economic benefit that arises when the share of the working-age population is large compared with dependants, during the transition. It can raise savings and growth if there are enough jobs, skills and health care, otherwise a large young population can become a burden.

PYQ Practice — Statement Analysis

1 In the early expanding stage the death rate falls while the birth rate remains high.

True

This causes rapid growth.

2 Replacement level fertility is about 2.1 children per woman.