Definition of Terms

  • Population: It is the total number of people living in a given area at a given time.
  • Population distribution: It refers to the spread of a population in a given area. It could be sparsely, moderately or densely distributed.
  • Population density: It is the average number of people living in a given area per squared kilometers.
  • Birth Rate: It is the average number of children born per 1000 population per year.
  • Death Rate: it is the number of people who die per 1000 people per year.
  • Fertility Rate: It is the average number of children that a woman is expected to bear in her lifetime.
  • Infant mortality: It is the number of babies who die before their first birthday, per live birth.
  • Child Mortality: It is the number of children who die before their fifth birthday, per live birth.
  • Demography : concerned with the study of human populations.
  • Population Structure: The structure of a population describes the distribution of the population in terms of the sex and age groups.
  • Population Pyramid: Population pyramid is a graph that depicts the structure of the population in terms of the sex and age groups.
  • Youthful Population: A youthful population is the population within the age groups of 0-14. It is also called the children population.
  • Working Population:The working population is the age group that ranges between 15 and 64. There are two types: the economically active (those actively working)and the economically inactive population (those who are unemployed or still in school).
  • Ageing Population: This is the age group above 64 year. They are also called the elderly population
  • Dependency Ratio: The dependent population is the population consisting of the youthful and elderly population. The dependency ratio is the ratio of the dependent population to the working or economically active population. It is calculated in the formula:DR = (0-14) + (65+)/(15 – 64)
  • Pro-natalist Policy: A Policy aimed at increasing the population or birth rate of a country. Eg. France, Sweden and Singapore have pro-natalist policies.n
  • Anti-Natalist Policy: A policy that is aimed at reducing population growth or birth rate. E.g China’s One-Child Policy.
  • Migration: the movement of people from one place to another, either permanently, seasonally, voluntarily or forced. It involves a change in residence. Daily commuters are not generally considered migrants. There are two main types of migration. These are
  • External Migration: migration across national boundaries. It is also called International migration
  • Internal Migration: Movement of people within a country.
  • Natural change – changes in population due to changes in birth and death rates.
  • Natural increase – increase in population due to an increase in birth over death in a country.
  • Natural decrease – decline in population due to an increase in death over birth in a country.
  • Population momentum – it is the tendency for population to grow despite a fall in birth rate and fertility levels. This happens when the number of women of childbearing increases in number such that they give birth faster than the death rate. This has the tendency of causing the population to increase astronomically.
  • Population Projection – these are future population estimates based on the current age-gender structure/fertility, mortality and migration
  • Doubling time: it is the period of time taken for population to increase twice its size, assuming natural growth rate remains unchanged.
  • Replacement rate: – it is the level at which each generation has enough children to replace themselves in a given population.

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