Core: Changing populations
Changing populations
This sub-unit examines migration and population change at different scales, including ageing, policy responses and the transformation of places. It tests whether you can explain change rather than just describe a pyramid.
Core rules
- Migration is movement between places; net migration is immigration minus emigration. Push factors include low wages and conflict; pull factors include jobs and services. Lee's model adds intervening obstacles.
- Types: voluntary economic migration, forced migration, refugees under the 1951 Refugee Convention, asylum seekers and internally displaced people (IDPs).
- Age-selective migration changes both source and destination. Young adults leaving rural areas raise the old-age dependency ratio (population 65+ divided by population 15–64).
- Ageing populations raise pension and healthcare costs and can shrink the labour force; responses include raising retirement ages, immigration and pronatalist incentives.
- Pronatalist policies include Russia's maternity capital and Japan's childcare subsidies. Antinatalist policies include China's one-child policy (1979–2015) and later three-child policy.
- Remittances can support households but may deepen dependence and inequality.
Worked example
A mountain region loses young adults to the capital city. Reasoning: push factors are low wages, limited higher education and poor services; pull factors are jobs and healthcare. Because migrants are young, the source area ages quickly and its old-age dependency ratio rises. School closures follow, creating a positive feedback that makes the area less attractive. Remittances may keep households afloat, but they do not replace the lost tax base. Policy must create year-round employment, not just build roads.
Traps
- Describing all migrants as refugees.
- Ignoring gender in migration flows.
- Assuming remittances always reduce local inequality.
- Confusing population ageing with population decline.