3. Population structure

• Population structure


  The characteristics of a population, the distribution of age, sex, ethnicity, religion etc.
• Changes in population structure

  1. Fertility

  2. Mortality

  3. Migration
• Population pyramid


  Used to display the gender and age structure of a given population
• Population pyramids


  • Illustrate the distribution of the population across age groups and between male/female
  • Enable governments to assess the needs of the population for services such as healthcare and education
  • Governments can estimate and plan for spending
• As countries develop and pass through the demographic transition

  The shape of the population pyramid changes
• Population groups identified in a population pyramid

  • Young dependents
  • Old dependents
  • Economically active (working population)
• Dependency ratio


  (young dependents+old dependents/working population) x 10
• Population pyramid - Niger

  • LEDC, concave shape, high birth rate, low life expectancy, high death rate, high infant mortality, young dependent population dominates
• Population pyramid - Nepal

  • LEDC/NIC, convex shape, decreasing birth rate, increasing life expectancy, decreasing death rate, decreasing infant mortality, larger working age population
• Population pyramid - USA

  • HIC, column shape, decreasing birth rate, increasing life expectancy, decreasing death rate, low infant mortality, larger working age population
• Population pyramid - Japan

  • HIC, pentagon shape with narrowing base, decreasing birth rate, increasing life expectancy, death rate higher than birth rate, low infant mortality, ageing population - older dependent population
• Implications of population structure

  • Ageing populations
  • Falling birth rates
  • Impacts of migration
• Ageing populations


  Increased pension payments, need for care homes, pressure on healthcare and social care, fewer workers, governments unable to collect as much tax, worker shortages
• Falling birth rates


  School closures due to fewer children, future workforce shortages
• Migration


  Can lead to imbalance in population structure, increased pressure on services, shortage of housing, increased traffic, pollution, water and food shortages
• When interpreting a population pyramid you need to look at four key areas: young dependents, working population, old dependents, male/female split