1. The interpretation of age / sex pyramids

2. POPULATION STRUCTURE:
 is the number of males and females in
different age groups.
 The common method to show the structure
is by a population pyramid.
 This diagram is made up by putting two bar
graphs (one for male, one for female) side
by side.
 From this you can read off what percentage
of a population is of a certain gender and
age range.

3. Key things to know about population pyramids:
 Population is divided into 5 year age groups.
 Horizontal line represents the percentage of male
& female group
 The age groups are divided into 3 groups:
 Young dependent (0-14 years old)
 Working Population (15-64 years old)
 Elderly Dependent (65+ years old)
 Population is divided into males and females.
 The percentage of each age /sex group is given.

4. What does the shape of the
population pyramids tell us?
 Information of birth and death rates
 Information of life expectancy
 People living in a particular country or
place

7. Comparing LEDC & MEDC

10. Three general profiles of population pyramids:
 Rapid growth: indicated by a pyramid with large
percentage of people in the younger ages
 Slow growth: reflected by a pyramid with a
smaller proportion of the population of the
younger ages.
 Zero population or decreasing populations:
shown by roughly equal numbers of people in all
age ranges, tapering off gradually at the older
ages

12. The population pyramid for
Kenya:
 Typical of a country in
the LEDCs experiencing
rapid population growth
 Wide base -large
numbers of dependent
children aged 0-14 as a
result of high fertility
rates
 Top of the pyramid
indicates smaller
proportion of the
population lives to old
age.

13. Implication of this type of population structure
(rapid growth):
 Limited resources will be stretched to meet
the needs of the large number of dependent
children for schooling, nutrition and health
care.
 As this group reaches working age, a large
number of jobs will be needed
 As this group reaches child bearing age, it is
likely that fertility rates will be high leading to
high rates of natural population increase

14. The population pyramid for the USA:
 Typical for MEDC
experiencing slow rates of
natural increase
 Narrow base reflects low
birth rates
 Wider top of the pyramid is
the result of people living
longer
 The bulge in 30-40 age
cohort is a result of the baby
boom of the 1960s

15. The population pyramid for
Germany:
 Is similar to that of USA
 It represents a zero-
population growth
(BR – DR = 0)
 People are distribute
evenly throughout the
cohorts

16. Implication of this type of population structure
 Ageing population
A smaller proportion of the working
age and are faced with the task of
generating enough wealth to
provide high levels of support for
the elderly population

17. Consequences of ageing
population
 Limited manpower for defense of a country
 Give pressure to government to provide more
medical and health facility for ageing population
 Shortage of labour, most of elderly retire and
not enough young people to replace them
 Need more housing facilities and transport to
meet the need of ageing population

18. Advantages of ageing population
 Tourism sector is boosted by the elderly
taking holidays during off-peak seasons
 Industriesthat tap into the pensioner
market (e.g. wheel chairs)
 Some large properties have been converted
to profitable residential homes

19. Dependency ratio
Dependency ratio = % of population aged 0-15 + % of population aged 65+
% 0f population of working age