2. Population structures
The rates of natural increase, births,
deaths, infant mortality and life
expectancy all affect the population
structure of a country.
The population structure of a country
can be shown by a population or age-sex
pyramid.
3. Population pyramids show
The total population divided into five-
year age groups
the percentage of people in each of
those age groups
the percentage of males and females in
each age group
4. Population pyramids are useful
because they show:
Trends in the birth rate, death rate, infant mortality
rate and life expectancy - these trends can help a
country to plan its future services, e.g. more homes
for the elderly if there is an ageing population or
fewer schools if there is a declining birth rate.
The effects of people migrating into or out of a
region or country.
The proportion of the population who are economically
active and the proportion who are dependent upon
them (dependency ratio).
5. Key things to know about
population pyramids:
• The shape of a population pyramid gives
us information about birth and death rates
as well as life expectancy.
• A population pyramid tells us how many
dependants there are living in an area.
There are two groups of dependants;
young dependants (aged below 15) and
elderly dependants (aged over 65).
6. Key things to know about
population pyramids:
Those of working age are classed as
economically active. Dependants
rely upon the economically active for
economic support.
Many LEDCs have a high number of
young dependants, whilst many
MEDCs have a growing number of
elderly dependants.
7. How may a pyramid change over
time?
• A population pyramid that is very
triangular (eg Mozambique in 2000)
illustrates a population with a high number
of young dependants and a low life
expectancy.
• A population pyramid that has fairly
straight sides (more like a barrel)
illustrates a population with a falling birth
rate and a rising life expectancy.
8. How may a pyramid change over
time?
Over time, as a country develops, the
shape of its population pyramid changes
from a triangular shape to a barrel-like
shape with straighter edges.
Places that are experiencing an ageing
population and a very low birth rate may
have a population structure that looks a
little like an upside-down pyramid.
9.
10.
11.
12.
13. Can you Interpret population
Pyramids
Six things to comment on
1. Birth Rate
2. Death Rate
3. Infant mortality
4. Life expectancy
5. % of dependants to economically
active
6. Migration
14. World population pyramid
animation
http://www.ined.fr/jeux.php?
_movie=chargement.swf?
_movie=simulateur.swf&lg=en&titre
=Population
simulator&lg=en&jeu=ok
23. Dependency ratios
The population of a country can be
divided into two categories according
to their contribution to economic
productivity. Those aged 15-65 years
are known as the economically active
or working population; those under
15 (the youth dependency ratio) and
over 65 (the old age dependency
ratio) are known as the non-econo-
mically active population.
24. The dependency ratio can be
expressed as:
children (0-14)
and elderly (65 and over)x 100
those of working age
http://news.bbc.co.uk/2/hi/south_asia/6911544.stm
India’s dependency ratio 2008
25. e.g. UK 1971 (figures in millions):
13 387 + 7307 x100 = 65.45
31616
So for every 100 people of working
age there were 65.45 people
dependent upon them
26. By 1999 the dependency ratio had
changed to:
11 345 + 9 271 x 100 = 53.55
38 498
So although the number of elderly people
had increased, this was more than offset
by the larger drop in the number of
children (the dependency ratio does not
take into account those who are
unemployed). The dependency ratio for
most developed countries is between 50
and 70, whereas for less economically
developed countries it is often over 100.
30. How will the structure of population A impact on
the provision of 2 social services? HSC Short Ans
Due to population As structure the provision of social
services is going to be difficult.
There is a small working age population to support the
young average population. This will make it difficult for
Population A to raise enough tax revenue to provide health
and education services.
How will the structure of population B impact on the
provision of 2 social services?
Due to the ageing population structure of Population B this
will impact on the provision of social services. The provision
of health and aged care facilities for the ageing population
will be difficult as the average age of Population B is getting
older. The proportionately smaller working age population
will have more dependents to support which will impact on
the ability of the government to raise tax money for the
provision of social services.
