1. Population Growth and Transitions
Age Structure Diagrams

3. What do population pyramids show?
A population pyramid (or age structure diagram) is a graphical representation of the number of people of each gender and age group within a population

4. Fast growth – Youthful population
Focus: What is the shape of a fast growing population? Why do you think that is?

5. Slowing growth
Focus: How can you tell the population growth is slowing?

6. Focus: What is the shape of a stable population chart?

7. Negative growth – Aging population
Focus: What is the shape of a negative growth age pyramid?
Negative growth – Aging population

8. Focus: How do the age pyramids for developing and developed countries differ?

9. Why is it important to understand the structure of population pyramids?
Planning for services at every level
How many schools will we need in 10 years?
What will we do to support an aging population?
Do we have enough people at the base to economically support or care for those at the top?

10. Does age structure change over time?
Focus: What happened to all of the young people from 1955? Where is their bar in the 2009 chart?

11. Quick Think: How might the Baby Boom generation show up in an Age Structure Diagram?

12. Why do countries continue to grow, even if the total fertility rate falls below the replacement level?
 Population momentum: a relatively large, younger generation still needs to pass through their child bearing years + life expectancy generally increases as a country develops
Focus: Make sure you understand the concept of population momentum!