World Population: Distribution, Density and Growth

Why this chapter matters for UPSC: Population is where human geography begins: where people live and why, how fast their numbers change, why they move, and how births and deaths change as societies develop. Prelims tests the distribution factors, NCERT's examples, the growth concepts and the demographic transition; Mains asks why distribution is uneven, why people migrate and what falling fertility means. In the 2026-27 NCERT reprint this is still Chapter 2, but shortened: it drops the region-wise density table, the sections on trends in population growth, doubling time, the spatial pattern of change and the impact of population change, and the note on the age and sex selectivity of migration. Everything else, including migration and the three-stage demographic transition, is unchanged. This page also carries the international-migration material that used to sit on a separate page.

Contemporary hook: Two recent UN reports show both halves of this chapter in motion. The UN's World Population Prospects 2024 estimates the world at 8.23 billion in mid-2025, growing at 0.84% a year, slower than in any year since 1950 except the pandemic year 2021 (0.80%), and India at 1.46 billion, the most populous country. And UNHCR's Global Trends report of June 2026 records that forced displacement fell during 2025 for the first time in a decade, to 117.8 million people, as refugees and displaced people returned to Afghanistan, Syria and other countries.

🧠 First Principles — Read This First

People are spread very unevenly, for reasons you can list. NCERT's headline is that about 90% of the world's people live on about 10% of its land. George B. Cressey's remark about Asia, that it "has many places where people are few and few places where people are very many", holds for the world. The reasons fall into three groups: geographical (water, landforms, climate, soils), economic (minerals, urbanisation, industrialisation) and social and cultural (religious significance, unrest, government incentives). Density, the number of people per square kilometre, measures the result.

Population changes in only three ways: births, deaths and migration. Natural growth is births minus deaths; actual growth adds in-migration and subtracts out-migration. The demographic transition describes how births and deaths change as a society moves "from rural agrarian and illiterate to urban industrial and literate": both high at first, then deaths falling while births stay high (the period of rapid growth), then both low. Migration redistributes people according to the push of the place they leave and the pull of the place they go to. Distribution, growth and movement are the three questions of this chapter.

PART 1 — Quick Reference

Factors Influencing Distribution (NCERT)

Growth Concepts and Rates (NCERT)

The World's Most Populous Countries (UN WPP 2024, mid-2025)

NCERT says the ten most populous countries hold "about 60 per cent" of the world's people, six of them in Asia. In the 2025 figures the ten hold about 57%; five are wholly in Asia, and six if Russia, which spans Europe and Asia, is counted.

NCERT's Demographic Transition, and India's Own

PART 2 — Concepts & Narrative

Patterns of Distribution and Density

NCERT opens with Emerson's line, "Not gold but only (Wo)men can make a people great and strong", and the reminder that "the people of a country are its real wealth". Population distribution is "the way people are spaced over the earth's surface". It is uneven at every scale: about 90% of the world's people live on about 10% of its land, and the ten most populous countries hold well over half of humanity (see the table above).

Density relates people to land: "Each unit of land has limited capacity to support people living on it." It is population divided by area, in persons per square kilometre. NCERT's worked example: a region of 100 sq km with 1,50,000 people has a density of 1,500 persons per sq km. India's density was 382 persons per sq km in 2011, up from 117 in 1951 (NCERT, India: People and Economy).

Why People Live Where They Do

Water comes first: it is needed for drinking, bathing and cooking, for cattle, crops, industry and navigation, so river valleys are among the most densely populated parts of the world. Landforms matter because flat plains and gentle slopes suit crops, roads and industry, while mountains hinder transport; the Ganga plains are among the most densely populated areas of the world, and the Himalayan zones are sparsely populated. Climate repels people at its extremes (very hot or cold deserts, very heavy rainfall) and attracts them where it is comfortable with little seasonal variation, as in the Mediterranean, settled since early history. Soils matter because fertile loamy soils support intensive agriculture.

Economic factors pull people to new places. Mineral deposits attract industries and workers (the Katanga-Zambia copper belt). Cities offer jobs, schools, hospitals, transport and amenities, so rural people migrate to them and "mega cities of the world continue to attract large number of migrants every year". Industrial belts employ not only factory workers but transport operators, shopkeepers, bank staff, doctors and teachers (the Kobe-Osaka region of Japan). Social and cultural factors complete the list: places of religious or cultural significance draw people, places of social and political unrest push them away, and governments sometimes offer incentives to live in sparsely populated areas or to leave overcrowded ones.

Population Growth and Its Components

Population change "may be positive as well as negative" and is an indicator of economic development, social progress and a region's history. NCERT's example uses India's census: subtracting the 2001 population from the 2011 population (121.02 crore) gives a growth of about 18.15 crore. (NCERT's text prints the 2001 figure as 102.70 crore; NCERT's own India: People and Economy gives 1,02,86,10,328, or 102.86 crore, and with that figure the subtraction gives the 18.15 crore the text states.)

The three components of change are births, deaths and migration. The CBR and CDR (formulas in Part 1) are per thousand of the mid-year population. NCERT notes that mortality depends on a region's demographic structure, social advancement and level of economic development, and that population grows "not only by increasing births rate but also due to decreasing death rate".

Migration

Migration is the third component of change. The place people leave is the place of origin, which loses population; the place they go to is the place of destination, which gains it. NCERT describes migration as "a spontaneous effort to achieve a better balance between population and resources".

• By duration: permanent, temporary or seasonal.
• By stream: rural to rural, rural to urban, urban to urban and urban to rural.
• By direction: immigrants move into a new place; emigrants move out of one. The same person is both: an emigrant from the place of origin and an immigrant at the destination.

People migrate for a better economic and social life, under two sets of factors (NCERT):

The 2021-22 text also noted that migration to cities is "traditionally age and sex selective", with more men of working age moving to cities; the 2026-27 reprint drops that line.

International Migration Today

The push and pull lists explain movement across borders as well as within them, and the numbers are now large:

• Migrants: the UN's International Migrant Stock 2024 counts 304 million international migrants in 2024, nearly double the 154 million of 1990, but still only 3.7% of the world's people. India is the largest country of origin: 18.5 million people born in India lived abroad in 2024, ahead of China (11.7 million) and Mexico (11.6 million).
• Forced displacement: UNHCR's Global Trends report (June 2026) estimates 117.8 million forcibly displaced people at the end of 2025. Forced displacement fell during 2025 for the first time in a decade, driven by returns: nearly 4.4 million refugees went home in 2025, over 90% of them to just three countries, Afghanistan, Syria and Sudan. The total includes 41.6 million refugees (including about 6 million Palestine refugees under UNRWA), 9 million asylum-seekers and 68.7 million internally displaced people (the Internal Displacement Monitoring Centre's estimate). Refugees and asylum-seekers have crossed a border; internally displaced people have not.

India's diaspora. The Ministry of External Affairs' table "as of January 2026" counts 3,72,80,845 overseas Indians: 1,95,20,317 Persons of Indian Origin (PIOs) and 1,77,60,528 Non-Resident Indians (NRIs, Indian citizens living abroad). The largest communities are in the USA (60.8 lakh), the UAE (43.4 lakh), Canada (32.5 lakh), Malaysia (29.0 lakh) and Saudi Arabia (27.5 lakh). The pattern follows two migration streams: older settlement and recent skilled migration (most overseas Indians in the USA, Canada and Malaysia are PIOs), and contract labour to the Gulf (nearly all of those in the UAE and Saudi Arabia are NRIs).

Remittances. The money migrants send home is the main economic link back to the place of origin. The World Bank's Migration and Development Brief 40 (June 2024) estimated India's remittance inflow in 2023 at $120 billion, the largest of any country, ahead of Mexico ($66 billion) and China ($50 billion). The RBI's balance-of-payments data show the flow still rising: personal transfer receipts, "mainly representing remittances by Indians employed overseas", reached US$ 43.5 billion in January-March 2026, against US$ 33.9 billion a year earlier.

India's law on foreigners. The Immigration and Foreigners Act, 2025 came into force on 1 September 2025 (S.O. 3981(E)). It repealed the Passport (Entry into India) Act, 1920, the Registration of Foreigners Act, 1939, the Foreigners Act, 1946 and the Immigration (Carriers' Liability) Act, 2000, so references to the Foreigners Act, 1946 as the governing law are out of date.

Trends in Population Growth (2021-22 text)

The 2021-22 text, dropped from the 2026-27 reprint, traces growth through history: about 8 million people after agriculture began some 12,000 to 8,000 years ago; under 300 million in the first century AD; about 550 million around 1750, at the dawn of the Industrial Revolution; then an explosion as the steam engine raised production and inoculation, medicine and sanitation brought death rates down. It took "more than a million years" to reach one billion, but only 12 years to go from 5 to 6 billion. NCERT's Table 2.2 of doubling times:

The projection has been overtaken: the UN's World Population Prospects 2024 estimates 8.02 billion on 1 July 2022, so the doubling from 4 to 8 billion took about 48 years, not 51. NCERT's 12 years from 5 to 6 billion matches WPP 2024 (5.05 billion in mid-1987, 6.01 billion in mid-1998). The figure below shows the series since 1950 (2.49 billion that year) with the annual growth rate, which peaked at 2.28% in 1963 and was 0.84% in 2025.

The same dropped section made two points that remain true. Growth is lower in developed countries than in developing ones: NCERT calls this a "negative correlation between economic development and population growth". And a small rate applied to a very large population still adds large numbers: world growth in 2025 is under 1%, yet the world adds tens of millions a year.

Demographic Transition

Demographic transition theory "can be used to describe and predict the future population of any area". As a society moves from rural, agrarian and illiterate to urban, industrial and literate, its population moves from high births and high deaths to low births and low deaths; the stages are together called the demographic cycle. NCERT teaches three stages (and its exercise asks for exactly three):

1. Stage I: high fertility and high mortality. People have many children to make up for deaths from epidemics and an uncertain food supply. Growth is slow, most people farm and large families are an asset, life expectancy is low, literacy and technology are low. Two hundred years ago all countries were in this stage.
2. Stage II: fertility high at first, then declining; mortality falling. Better sanitation and health care bring death rates down first, so the gap between births and deaths, and the net addition to population, is large.
3. Stage III: both fertility and mortality low. Population is stable or grows slowly; people are urban, literate and technically skilled, and deliberately limit family size.

NCERT's Fig. 2.3 labels the stages "high fluctuating", "expanding" and "low fluctuating", with birth and death rates of about 35 per thousand in Stage I and about 15 in Stage III. Its examples (from the original edition) place rainforest tribes and Bangladesh in Stage I, Peru, Sri Lanka and Kenya in Stage II, and Canada, Japan and the USA in Stage III. Those placements have aged: UN WPP 2024 gives Bangladesh a CBR of 20.4 and a CDR of 5.0 per thousand in 2023, which is a late-transition profile, not Stage I. NCERT's lesson stands: "human beings are extremely flexible and are able to adjust their fertility", and "different countries are at different stages".

India's transition in numbers (UN WPP 2024): in 1950 India's CBR was 44.1 and its CDR 22.7 per thousand; by 1990 they were 32.6 and 10.7; by 2023, 16.1 and 6.6. India's total fertility rate is now below the replacement level of 2.1: the Sample Registration System puts it at 1.9 in 2024, with Bihar (2.9) and Uttar Pradesh (2.6) the highest among the bigger States and Delhi (1.2), Tamil Nadu, Kerala and West Bengal (1.3 each) the lowest (SRS Statistical Report 2024). Japan shows what lies beyond NCERT's last stage: in 2023 its CBR was 6.0 and its CDR 12.3, so deaths outnumbered births.

Population Control and Malthus

Family planning, the spacing or preventing of births, and access to family-planning services limit population growth and improve women's health; publicity, free contraceptives and tax disincentives for large families are other measures (NCERT). Thomas Malthus (1798) argued that population would grow faster than food, until famine, disease and war caused a crash; NCERT adds that preventive checks are better than physical checks, and that "for the sustainability of our resources, the world will have to control the rapid population increase".

Population Change and Its Impact (2021-22 text)

NCERT's dropped section argued that a small increase in population is desirable in a growing economy, but growth beyond a point depletes resources, which is "the most serious" problem; a decline is also a concern, since it suggests that resources which supported a population are no longer enough. It also noted that the HIV/AIDS epidemics in Africa, parts of the CIS and Asia had pushed up death rates and slowed growth. Its line that India's annual growth rate "is 1.64 per cent" is out of date: UN WPP 2024 gives 0.88% for 2023.

PART 3 — UPSC Integration

Frames that score. For "why is world population unevenly distributed?", use NCERT's three groups of factors, each with its NCERT example, and end with a dated density figure. For "discuss the three stages of demographic transition", follow NCERT's three stages exactly, then add a dated Indian application (CBR and CDR from the UN; TFR from SRS 2024). For migration, define the origin, destination and streams, use the push-pull table, then add one current figure for each scale (India's diaspora, 2026; world migrants, 2024; forced displacement, 2025).

Dates matter here more than anywhere. Population figures change every year and come from different series: the census (India 2011), SRS (fertility, 2024), UN WPP 2024 (estimates to 2023, projections after), MEA (diaspora, January 2026), UNHCR (displacement, end-2025). Name the series and year every time.

Exam Strategy

For Prelims: Learn the three factor groups with NCERT's examples (Katanga-Zambia, Kobe-Osaka, Ganga plains, Mediterranean), the CBR and CDR formulas, the definitions of natural and actual growth, the push and pull lists, the four migration streams, and the three DTM stages with their features. Know the current top countries and India's TFR (1.9, SRS 2024).

For Mains: Use NCERT's structure as the skeleton and current, dated data as evidence. Keep NCERT's three-stage model in answers that quote NCERT; if you use a four- or five-stage version, say so.

Avoid: NCERT's outdated numbers presented as current (India's growth "1.64 per cent"; 8 billion "projected" for 2025; Bangladesh in Stage I), and mixing data sets in one sentence (an SRS national figure with NFHS state figures).

Practice Questions

Practice (UPSC-pattern, not past papers). Questions 1 to 4 are NCERT's own exercise MCQs.

Prelims:

1. Which one of the following continents has the highest growth of population?
   (a) Africa
   (b) South America
   (c) Asia
   (d) North America

2. Which one of the following is not an area of sparse population?
   (a) The Atacama
   (b) South-east Asia
   (c) Equatorial region
   (d) Polar regions

3. Which one of the following is not a push factor?
   (a) Water shortage
   (b) Medical/educational facilities
   (c) Unemployment
   (d) Epidemics

4. Which one of the following is not a fact?
   (a) Human population increased more than ten times during the past 500 years.
   (b) It took 100 years for the population to rise from 5 billion to 6 billion.
   (c) Population growth is high in the second stage of demographic transition.
   (d) Mortality depends on a region's demographic structure, social advancement and economic development.

5. "Actual growth" of population in a region equals:
   (a) births − deaths
   (b) births − deaths + emigration − immigration
   (c) births − deaths + in-migration − out-migration
   (d) in-migration − out-migration

6. Consider the following statements:
   

   1. According to the Sample Registration System, India's total fertility rate in 2024 was 1.9.
      
   2. According to UNHCR, the number of forcibly displaced people fell during 2025.
      
   3. India is the largest country of origin of international migrants (UN DESA, 2024).
      Which of the statements given above are correct?
      (a) 1 and 2 only
      (b) 2 and 3 only
      (c) 1 and 3 only
      (d) 1, 2 and 3

7. In NCERT's three-stage demographic transition, the net addition to population is highest in:
   (a) the first stage, because fertility is high
   (b) the second stage, because mortality falls while fertility is still high
   (c) the third stage, because the population is urbanised
   (d) all stages equally

Note on Q4: NCERT's own option (c) reads "Population growth is high in the first stage of demographic transition", which is itself false (growth is slow in Stage I), leaving two "not a fact" options; it has been reworded here so that (b) is the single answer.

Mains:

1. Discuss the geographical, economic and social factors influencing the distribution and density of world population, with examples. (250 words)
2. Discuss the three stages of demographic transition. Where does India stand today? Support your answer with dated data. (250 words)
3. Distinguish between push and pull factors of migration. How do they explain the pattern of India's diaspora and its remittances? (250 words)

📦 Revision Capsule

Sources

• NCERT, Fundamentals of Human Geography (Class XII), ch. 2 "The World Population: Distribution, Density and Growth", 2021-22 print and Reprint 2026-27: 2021 book archive, 2026 book archive.
• NCERT, India: People and Economy (Class XII), ch. 1 "Population: Distribution, Density, Growth and Composition", Table 1.1 and density, Reprint 2026-27: book archive, Wayback copy.
• UN DESA Population Division, World Population Prospects 2024, demographic indicators and population by age and sex (medium variant): population.un.org/wpp.
• Office of the Registrar General and Census Commissioner, India, Sample Registration System Statistical Report 2024, Statement 24: SRS_STAT_2024.pdf.
• UN DESA Population Division, International Migrant Stock 2024: Key facts and figures and origin dataset: key facts PDF, dataset.
• UNHCR, Global Trends: Forced Displacement in 2025 (June 2026): report PDF.
• Ministry of External Affairs, "Population of Overseas Indians" (data as of January 2026; page updated 26 May 2026): mea.gov.in.
• World Bank and KNOMAD, Migration and Development Brief 40 (June 2024): documents.worldbank.org.
• Reserve Bank of India, "Developments in India's Balance of Payments during the Fourth Quarter (January-March) of 2025-26", 8 June 2026: rbi.org.in.
• Ministry of Home Affairs, notification S.O. 3981(E) of 31 August 2025 (commencement of the Immigration and Foreigners Act, 2025) and the Act's text: notification, Act.