1. Population Pyramids

2. What are Population Pyramids and what do they show?
Bar graphs used to show the age and sex structure of a population
Vertical axis: Represents various age groups
Horizontal axis: Shows either the actual number or the proportion of the population for both males and females
Each population pyramid represents 100% of a particular population

3. Expanding population pyramids
Show larger numbers or percentages of the population in the younger age groups, usually with each age group larger in size or proportion than the one before
Population growth is rapid
Base is wide means: High birth rate= ‘young’ population

4. Contracting population pyramids
Displays lower numbers or percentages of younger people
Low birth rates
Upper part is wider: ‘Ageing’ or ‘old’ population

5. Stable population pyramids
Displays somewhat equal numbers or percentages for almost all age groups
Smaller figures are still to be expected at the oldest age groups
Population growth is neutral or stable

6. Fluctuating population pyramids
Shows larger numbers or percentages of the population in some age groups, and smaller in other age groups
Possible reasons: Effects of war and/ or migration

7. Expanding influx of young males population pyramids
Population Pyramid United Arab Emirates 2005
Displays a high number of young males and only a small number of females in comparison
Possible reason: Mining town- influx (arrival) of economically active males

8. Rural out-migration of young males population pyramids

9. Rural out-migration of young males population pyramids
Displays a smaller number of economically active young males, who often return to the countryside when they have earned sufficient money
Rural population= mostly young children, women and old people

10. How to Read a Population Pyramid
Width of the Base (children between 0-14 years old)
Birth rate varies with the width of the base
Wide base indicates a high birth rate
Narrow base indicates a low birth rate

11. How to Read a Population Pyramid
Width of the Middle (working adults between years old)
Wide middle indicates a high number of economically active people
Narrow middle indicates a low number of economically active people

12. How to Read a Population Pyramid
Width of the Top (older/ retired people 65+ years old)
Wide top indicates an aging population
Narrow top indicates lower life expectancy

13. How to Read a Population Pyramid
Symmetry
Ideal: pyramids should be relatively symmetrical
Any asymmetry indicates a difference in the male and female population
Example of Russia 2011: pyramid shows more females at age ranges above 50 which indicates that women are living to older ages than males

14. How to Read a Population Pyramid
Shape of Sides
Curved in sides indicate a high death rate
Slightly rounded sides indicate a low death rate
Example Haiti 2011: population pyramid exhibits curved sides indicating a high death rate

15. How to Read a Population Pyramid
Bumps in the sides
Irregularities in the sides indicate a demographic anomaly
Example USA 2000: age group in the population pyramid at the right represents the baby boom; this bump will travel upward as the baby boomers age
Example Bahrain 2011: large numbers of working aged men in the pyramid to the left indicates a migrant workforce