Population movements — migration — are the third determinant of population change alongside births and deaths. Understanding the types of movement, their causes, and their demographic effects is essential for Unit 4.
Population movements can be classified along several dimensions:
| Type | Definition | Examples |
|---|---|---|
| Voluntary | Migrant chooses to move, usually for economic or lifestyle reasons | Labour migrants, retirement migrants, lifestyle movers |
| Forced | Migrant compelled to move by threat of violence, persecution or disaster | Refugees, internally displaced persons (IDPs), environmental refugees |
| Type | Definition | Examples |
|---|---|---|
| Internal | Movement within a country | Rural-to-urban migration, inter-regional movement, seasonal movement |
| International | Movement between countries | Economic migrants, refugees crossing borders, diaspora movements |
| Type | Definition | Examples |
|---|---|---|
| Temporary | Short-term movement with return expected | Seasonal agricultural workers, circular migrants, gastarbeiters |
| Long-term / Permanent | Settlement without intention to return | Family migration, refugee resettlement, emigration |
Rural-to-urban migration: The dominant form of internal migration globally since the mid-20th century. Driven by agricultural mechanisation (reduced rural labour demand) and urban economic opportunity. Africa is currently experiencing rapid urbanisation; many Asian cities grew through this mechanism in the 1970s–2000s.
Seasonal migration: Agricultural workers moving with planting/harvest cycles (e.g., wheat harvest workers in Australia; coffee pickers in Colombia).
Step migration: Movement in stages — from village to small town to large city — rather than directly to the destination.
Counterurbanisation: Movement from cities to rural/peri-urban areas, common in highly urbanised wealthy nations (UK, USA, Australia post-COVID).
Economic migration: Moving for employment or improved living standards. Examples:
- South Asian workers in Gulf states (temporary, often circular)
- Mexican migrants in the USA
- Eastern European workers in Western Europe (EU freedom of movement)
Refugee and asylum seeker movement:
- Defined under the 1951 UN Refugee Convention: a refugee is a person outside their country of origin who has a well-founded fear of persecution based on race, religion, nationality, political opinion, or membership in a particular social group
- 110+ million forcibly displaced worldwide in 2023 — record high
- Major source regions: Syria, Afghanistan, Ukraine, South Sudan, Myanmar
Brain drain: Skilled professional emigration from developing countries to wealthier nations (e.g., Indian IT workers to USA; African doctors to UK/USA). Creates human capital losses in origin countries.
The Lee Model (Everett Lee, 1966) formalises the push-pull framework:
Push factors (conditions in origin that encourage emigration):
- Poverty and unemployment
- Conflict and persecution
- Natural disasters (earthquake, flood, drought)
- Environmental degradation
- Political instability
Pull factors (conditions in destination that attract migrants):
- Employment opportunities and higher wages
- Political stability and rule of law
- Family or community networks (chain migration)
- Better education and healthcare
- Environmental amenity
Obstacles (factors that impede movement):
- Distance and transport cost
- Immigration restrictions (visas, borders)
- Language and cultural barriers
- Family ties to origin
- Financial poverty (limiting even voluntary migrants)
Intervening opportunities: Better option closer to origin may deflect migration before it reaches the intended destination.
Migration affects population in several ways:
For receiving countries/regions:
- Increases total population and labour supply
- Typically receives younger adults → lowers dependency ratio → stimulates economic growth
- Can change population structure (bulge in working-age cohorts)
- Introduces cultural diversity
- If large-scale, can drive urbanisation and strain infrastructure
For sending countries/regions:
- Reduces total population (sometimes net population decline in rural areas)
- Removes working-age adults → increases dependency ratio
- Remittances provide economic benefit to families remaining (global remittances ~\$800 billion/year — exceeding foreign aid)
- Brain drain reduces human capital
Case example: Australia’s migration programme adds ~190,000–210,000 permanent residents per year (pre-COVID), largely offsetting below-replacement fertility (TFR ~1.6) and maintaining working-age population share.
KEY TAKEAWAY: Population movements are classified by whether they are voluntary/forced, internal/international, and temporary/permanent. The push-pull framework explains most voluntary migration. Forced displacement is at record levels globally, driven by conflict and climate. Migration significantly affects population structure in both sending and receiving areas.
EXAM TIP: For any migration question, classify the movement type, explain using push-pull factors, and discuss the demographic impact on both sending and receiving regions. Never discuss migration only from the destination’s perspective.
COMMON MISTAKE: Confusing refugees with economic migrants. Use the legal definitions: refugees have fled persecution (1951 Convention), while economic migrants move voluntarily for livelihood improvement. Asylum seekers are awaiting determination of refugee status.
