1. Population Pyramids

2. How to read a population pyramid
Imagine 2 sideways bar graphs
Males – left
Females – right
Vertical axis
age
year of birth
Horizontal axis
Thousands
Millions
Percent
Year
3 types of pyramids…

3. Expansive type Triangle/pyramid Base – widest part
Birth rate – high or low? Note the concave sides
Death rate – high or low?
Rate of Natural Increase – high or low?
Which stage of Demographic Transition Model?

4. Stationary type Half ellipse shape
Base – about the same width as middle
Birth rate – high or low?
Death rate – high or low? Note the convex sides
Rate of Natural Increase – high or low?
Which stage of Demographic Transition Model?

5. Constrictive type Base – narrower than middle
In extreme cases, upside-down pyramid
Birth rate – high or low?
Death rate – high or low?
Rate of Natural Increase – high or low?
Which stage of Demographic Transition Model?

6. Asymmetry in Pyramids
typically, most pyramids show symmetry. Any asymmetry means . . .
a.) there is something that happened/happens that accounts for a difference in female and male population – examples: war, restrictive population policies, migrant workforce
b.) there was a baby boom

7. Population Pyramids for Several US Cities & Towns
(Upper left corner is the whole US.)

8. Dependency Ratio
Compares population of dependents (children and elderly) to working-age population
0-14
15-64
65+
Why do we use these ages?
What might be some problems with using these ages?
Percent of population under age 15 (darker color means higher percent)

9. Goldilocks Moment Too hot! Too cold! Just right.
Too young! Too old! Just right.
Low dependency ratio
Not too many children or elderly
Good for economy – why?

10. More pyramids to explore
Immigrants to US from various countries
US but link doesn’t work
Canada
Several major countries
Australia
World
Various, including some historical US, and WWII Germany
UK vs. Mozambique UK
China
India
Japan

11. Connecting to your project
Think about the country that you are researching for your Status of Development Project.
If you’ve already looked at your country’s population pyramid, use what you remember about it.
If you haven’t looked at it yet, make an educated guess based on what you know about the country.
Questions to consider:
How can you use what we learned today in your project?
What shape is your country’s population pyramid? Why?
What can you tell about your country from its pyramid?
Is there anything distinctive in your country’s pyramid? Why? What does it mean?
Examples - Very high or very low numbers of people in certain age groups? A sex imbalance? Etc.