Population
What changes population
- A country's population changes with three things:
- birth rate (births per 1000 people per year),
- death rate (deaths per 1000 per year),
- migration — immigration (in) minus emigration (out) = net migration.
- Population grows when births + immigration > deaths + emigration.
Practice
A country's population grows when:
Population rises when people added (births + immigration) exceed people lost (deaths + emigration).
Practice
Net migration is:
Net migration = people moving in (immigration) − people moving out (emigration).
Structure & ageing
- Population structure = the split by age and sex, drawn as a population pyramid.
- A developing country has a wide, youthful base; a developed country is more column-shaped (an ageing population).
- An ageing population means fewer workers per retired person, more spent on pensions/healthcare, so higher taxes or more migrant workers may be needed.
Practice
A problem of an ageing population is that there are:
Longer lives and fewer children mean fewer workers per retiree, raising pension and healthcare costs.
You've got it
Key idea
- population changes via birth rate, death rate, and net migration
- grows when births + immigration > deaths + emigration
- an ageing population = fewer workers per retiree → more pension/health spending