Why this matters now
Population distribution, the demographic transition and migration (push-pull, effects) are tested in prelims and link to India’s demography, urbanisation and society syllabus.
Distribution and density
World population is unevenly distributed — concentrated in fertile river valleys, plains and coasts (South and East Asia, Europe), and sparse in deserts, dense forests, high mountains and polar regions. Density is governed by physical (climate, water, landforms, soil), economic and socio-political factors.
Growth and the demographic transition
Population change depends on births, deaths and migration. The Demographic Transition Model (DTM) describes the shift from high birth/death rates (Stage 1) through rapid growth (Stages 2–3) to low birth/death rates and stable/declining population (Stages 4–5) as countries develop.
Migration
Migration is the movement of people, classified as internal (within a country) or international, and voluntary or forced (refugees). It is driven by push factors (poverty, conflict, disaster) and pull factors (jobs, safety, services). Effects include remittances, brain drain/gain, urbanisation, demographic change and social tensions.
UPSC angle
Know factors of population distribution/density, the Demographic Transition Model stages, migration types (internal/international, voluntary/forced), push-pull factors, and effects (remittances, brain drain).
Frequently asked questions
Why is world population unevenly distributed?
Because of physical (climate, water, landforms, soil), economic and socio-political factors that make some areas more habitable and productive.
What is the Demographic Transition Model?
A model describing how birth and death rates change as a country develops — from high rates through rapid growth to low rates.
What are push and pull factors in migration?
Push factors (poverty, conflict, disaster) drive people away; pull factors (jobs, safety, services) attract them to a destination.
What are the effects of migration?
Remittances, brain drain or gain, urbanisation, demographic change and sometimes social tensions.