Presentation on theme: "Population Pyramids by Gayle Robinson"— Presentation transcript:
Population Pyramids by Gayle Robinson
Population Pyramids Provide 3 types of information : – Age/gender distribution – Dependency ratio – Demographic Transition position
Age/Gender Distribution Each bar represents a 5-year increment beginning at 0. Males are shown on the left. Females are shown on the right.
Dependency Ratio Elderly population 65+ years of age Children 0-14 years of age Workforce
The Demographic Transition Model Low GrowthHigh growthModerate GrowthLow Growth Population Pyramid Shape
Stable Pyramid or Concave Triangular: Stage 1 Shape: Concave Triangular No country in Stage 1 today High Crude Birth Rate High Crude Death Rates and short Life Expectancy Low Growth Young population
Expansive or Triangular: Stage 2 High Birth Rate Decreased Death Rate Increased life expectancy High Growth Rate Young population Developed world entered this stage during Industrial Revolution This population pyramid is typical of countries in poorer parts of the world (LEDCs.)
Expansive or Triangular: Stage 2
MaleFemale Population in millions In this country there is a high Birth Rate There is also a high Death Rate. This population pyramid is typical of countries in poorer parts of the world (LEDCs.) Expanding pyramid
In some LEDCs the government is encouraging couples to have smaller families. This means the birth rate has fallen.
Stationary or Columnar: Stage 3 Birth Rate decreases through societal changes Death Rate continues to decrease Longer Life Expectancy Moderate Growth Ageing population This population pyramid is typical of countries in the richer parts of the world (MEDCs.)
Stationary: Stage 3
MaleFemale Population in millions In this country the number of people in each age group is about the same. The largest category of people were born about 40 years ago. In this country there is a low Birth Rate and a low Death Rate. This population pyramid is typical of countries in the richer parts of the world (MEDCs.) Stationary pyramid
Contractive or Inverted: Stage 4 Declining Birth Rate Low Death Rate Long Life Expectancy Larger number of elderly population Low Growth Ageing population.
Contractive: Stage 4
Population in millions MaleFemale In this country the birth rate is decreasing. In the future the elderly people will make up the largest section of the population in this country. This is happening more and more in many of the world’s richer countries. Contracting pyramid
There are narrower parts in the middle part of the pyramid. People in their 20s in 1961 were born during the Depression, a time of economic hardship in Canada when people were having fewer children. Spearhead pyramid The pyramid had a wide base. These are the “baby boomers,” a large group of people born between 1947 and 1966 when the economy was growing and prospering. This is caused by a war, a time of economic hardship, illnesses, famine...
Male Female Population in thousands This country has a large number of temporary workers. These are people who migrate here especially to find a job.
To sum up… Expanding pyramid Stationary pyramid Contracting pyramid LESS DEVELOPED COUNTRIES DEVELOPING COUNTRIES DEVELOPED COUNTRIES