Population Pyramids

Population Pyramids

Summary of Concepts

1.      Population Pyramid- it is a graph showing the structure of a country’s population according to age and gender (male or female). It is useful to compare the pyramids of two or more countries to see similarities and differences. The word pyramid comes from pyramids built during ancient Egypt, which looked like triangle from the side, ∆: Not all population pyramids are shaped like this.

2.      There four main types of Population Pyramid shape: Each shape tells us something special about the population in that country.

a)      Expanding population; there is rapid population growth, high BR and DR, high NI, low Life Expectancy, lots of young people and few old people. This pyramid looks like a classic triangle or pyramid (eg, Ethiopia: natural increase is 2.36%).

b)      Gradually expanding population: The population is growing slowly, BR is slightly greater than DR, Life Expectancy is longer and there are more middle-aged people. This pyramid can show a ‘bulge’ in the 20-40 age group (eg Mauritius; natural is 0,88%).

c)      Stable population: The population is more or less remaining the same, BR and DR are declining but similar, LE is longer and there is an ageing population (eg. Switzerland: natural increase is 0.13%).

d)      Declining population: The population is declining, DR exceeds BR, LE is long and there are more middle-aged and older people than young people. This pyramid has a narrowing base due to the decline in population (eg. South Africa: natural increase is-0,28%).

NB; The Intervals used on the horizontal axis (population) of each pyramid can vary.

3.      The government can use population pyramids for the future.

4.      Population pyramids can change over time. a pyramid of South Africa’s population in 2000 is different to one for 2010, 2020…….etc

5.      Dependency ratio: this tells us how many young and old people the working people in a population have to support.

Dependency Ratio (DR)= Number of children under 15yrs + adults over 60yrs÷ adults from 15yrs to 59 x100.

NB: Population pyramids for different countries will be attached to assist you to understand the role that they play to illustrate the structure of population according to age and sex. These pyramids help in understanding the differences that exist between developed countries and developing countries. They also reflect how different countries implement their policies in controlling population growth patterns with regards to Birth rates. They also indicate how well governments deal with social aspects of people’s lives that impact on their death rate and life expectancy.

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