Population and migration

• Population Density


  Average number of people per unit of area
• Crude birth rate


  Number of births per 1000 population
• Crude death rate


  Number of deaths per 1000 population
• Natural increase


  Percentage increase in population due to natural causes (births - deaths)
• Net migration


  Difference between immigration and emigration
• Total fertility rate


  Average number of children a woman has in her lifetime
• Infant mortality rate


  Number of deaths of children under 1 year old per 1000 live births
• Life expectancy at birth 


  Average number of years a newborn can expect to live under current mortality conditions
• Overpopulation


  Imbalance between population size and available resources
• under employment

  People working less than needed to earn a reasonable living
• Population policy


  Measures taken by government to influence population growth, distribution, composition
• Population policy measures


  • Promote larger families
  • Reduce population growth
• Population pyramid


  Graphical representation of the age and sex structure of a population
• Population pyramid


  • Shows percentage of young dependents (under 16)
  • Shows percentage of old dependents (over 65)
  • Shows working population (16-65)
• In 1950, the world population was 2.5 billion
• In 2022, the world population is 7.9 billion
• Demographic Transition Model (DTM)

  Describes the transition from high birth and death rates to low birth and death rates as a country develops
• Carrying capacity


  The maximum population a given environment can sustainably support
• Asylum seeker


  Person seeking refugee status in a country other than their own
• Push factors for migration

  • Natural disasters
  • War
  • Lack of jobs
  • Poverty
  • Persecution
• Pull factors for migration

  • Better job opportunities
  • Higher salaries
  • Better schools/healthcare
  • Joining family/friends
• China's One Child Policy was introduced in 1980 due to concerns over overpopulation
• In 2015, China's One Child Policy was replaced by a Two Child Policy
• China's One Child Policy was enforced through measures like fines, forced contraception, forced abortions, and having second children taken away
• China's One Child Policy prevented around 400 million births
• China's One Child Policy led to issues like an ageing population, gender imbalance, and abandoned children
• Botswana had high population growth rates in the 1990s due to the HIV/AIDS epidemic
• Botswana's population growth rate declined from 3.5% in 1994 to 1.4% in 2009 due to the impact of HIV/AIDS
• Mexico has experienced large-scale migration of guest workers to the US, with surges in the 1920s-1950s and more recently
• Factors driving Mexican migration to the US include higher wages, better job opportunities, and family reunification