1. Population Pyramids
by Gayle Robinson

2. Population Pyramids Provide 3 types of information:
Age/gender distribution
Dependency ratio
Demographic Transition position

3. Age/Gender Distribution
Males are shown on the left.
Females are shown on the right.
Each bar represents a 5-year increment beginning at 0.

4. Dependency Ratio Elderly population 65+ years of age Workforce
Children 0-14 years of age

5. The Demographic Transition Model
Low Growth
High growth
Moderate Growth
Low Growth
Population
Pyramid
Shape

7. 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

8. 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.)

9. Expansive or Triangular: Stage 2

10. Expanding pyramid Male Female
There is also a high Death Rate.
In this country there is a high Birth Rate
Population in millions
This population pyramid is typical of countries in poorer parts of the world (LEDCs.)

11. In some LEDCs the government is encouraging couples to have smaller families. This means the birth rate has fallen.

12. 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.)

13. Stationary: Stage 3

14. Stationary pyramid Male Female
Population in millions
The largest category of people were born about 40 years ago.
In this country the number of people in each age group is about the same.
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.)

15. Contractive or Inverted: Stage 4
Declining Birth Rate
Low Death Rate
Long Life Expectancy
Larger number of elderly population
Low Growth
Ageing population.

16. Contractive: Stage 4

17. Contracting pyramid
Male
Female
Population in millions
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.

18. Spearhead 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.
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...

19. Population in thousands
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.

20. LESS DEVELOPED COUNTRIES
To sum up…
Expanding pyramid
Stationary pyramid
Contracting pyramid
DEVELOPING COUNTRIES
DEVELOPED COUNTRIES
LESS DEVELOPED COUNTRIES