1. What do we mean by demography?
Study of human populations
Births
Deaths
Age
Gender
These variables can be shown in a population pyramid

2. Learning Objectives
To be able to construct and interpret population pyramids, and understand how population structures represent different stages of the DTM.

3. Population pyramids
A population pyramid displays the age – sex structure of a country or area
The height of the pyramid indicates life expectancy
The width of the base gives an indication of birth rate
The vertical axis shows the population in age bands of 5 years
Males to the left
The horizontal axis shows number or % of males and females
Females to the right

4. Look out for lumps and bumps!
Population structure
Look out for lumps and bumps!
Bulges or surpluses can show the effects of in migration or baby booms!
Dips or deficits can show the effects of out migration, war, famine or disease

5. Activity: The UK’s population structure
Complete the worksheet by labelling key factors that influence the shape of the UK’s population pyramid.
What stage of the DTM was the UK in at this time?

6. Check your answers Figure over 60 Females = 6.6 million
Over 90 years males = 0.2% females = 0.25%
2b) More females (3.7 million ) than males (3.2 million)
1a)
1c)
1b)
2a) fluctuating BR
1d)

7. Age structure can be measured using the Dependency Ratio
Population structure
Age structure can be measured using the Dependency Ratio
Elderly dependents
Economically active
Figures for calculating the dependency ratio can vary!
Youth dependents
The higher the dependency ratio, the more the non–economically active population is dependent on the working population
The dependency ratio = (population 0 – 19) + (population over 60)
population 20 – 59 years

8. Dependency ratio
Countries with a dependency ratio close to 1 have high dependency - they have 1 person of working age for every dependent person.
Dependency ratios of 0.5 are better; this means that for every 2 working age people there is only 1 dependent person to cater for.
High dependency can result from:
A high number of children giving a youthful population, in the Mali, over 40% of the population is under the age of 15.
A high number of elderly people, an ageing population.

9. The Juvenility Index = population 0 – 19 population 20 and over
Population structure
The Juvenility Index = population 0 – population 20 and over
The higher the index, the greater the proportion of younger people in the population
(LEDC’s)
Mozambique 2000

10. The Old Age Index = population 60 and over population 20-59
Population structure
The Old Age Index = population 60 and over population 20-59
The higher the index, the greater the proportion of elderly people in the population
(MEDC’s)
Figures for calculating the old age index can vary!
UK 2000

11. Activity: Drawing a population pyramid
Use the statistics in table 5.3 to draw a population pyramid for Kenya on the template provided:
Label the horizontal axis
Add an appropriate scale
Label male and females
Having drawn your pyramid, complete tasks 1-3 in the grey box on your sheet.
Complete the questions on page 2 of the Kenya booklet. Answer them in your book.

12. Learning Objectives
To be able to construct and interpret population pyramids, and understand how population structures represent different stages of the DTM.

13. What else does a population pyramid show?
The four pyramids display characteristics which suggest events within that country or the status of a country.
Study the pyramids to see if you can work out which characteristics fit each pyramid...
An LEDC
A birth control policy
An ageing population
A famine
A young population
An MEDC
A baby boom
A country which has been at war

14. Baby boom
War
Famine
An ageing population

15. Population structure: changes over time
As country or area develops, its population structure changes over time. The shape of pyramids reflect different stages in the Demographic Transition Model.

16. Activity: Population pyramids and the DTM
Cut out the population pyramids and stick them in your books in the correct order – stages 1 to 5.

17. Check your answers
Plenary – 10 things you know about population pyramids