Population Pyramids
Population Pyramids

A special graph that shows the make-up of a
population by age and gender.
Cohorts
A specific portion of
the population that is
combined together in
an age group for the
purposes of
simplifying a
population pyramid.
Five-year cohorts are
commonly used in
population pyramids.
The pattern
that is
created
gives clues
to the
nature of
country’s
population.
The percentage of
males is plotted on the
left
The percentage of
females is plotted on
the right
3 Types of Population Pyramids
1) Increasing Population:
A pyramid with a wide
base and narrower top.
This indicates a high birth
rate and an expanding
population.
2) Stable Population:
A pyramid that indicates
no or very little population
growth. The pyramid is
characterized by relatively
straight sides.
3 Types of Population Pyramids
3) Decreasing Population:
A pyramid with a narrow base
and a narrow top. This
indicates low birth rate and
high death rate.
Different Ages—Different Roles
Children (under 15)
 Working Adults (16-64)
 Older adults (65+)

Dependency Load: people under the age of 15 and over the age of 65.
These people are usually not active income earners and are often
supported by family members, pensions or retirement earnings.
Working Population: this is the actively working population. Usually
people between the ages of 15 and 64.
Dependency Ratio

The ratio between the number of dependants (anyone
above or below the working age) and the number of
people in the potential labour force. This ratio gives an
indication of the level of economic development in the
country as the higher the percentage of people of
working age a country has the better off economically
they should be.


young dependants (YD): Anyone younger than 15
old dependants (OD): Anyone 65 and older

Dependency ratio =
YD (%) + OD (%)
People of working age (%)
x 100
Demographic Transition

A multi-staged model showing changes in population as
a result of a country’s economic development. The
model is based on the changing population of Western
Europe during industrialization.
4 Stages of the Demographic
Transition Model
1) Primitive:
High birth & death rates,
moderately high population
growth, primitive health and
medical conditions, low life
expectancy rate, very poor
standard of living, least
developed countries (LLDCs).
2) Early Expanding:
High birth rate, death rate
drops dramatically, improved
medical conditions, largely
agricultural and rural
population, large families,
explosive population growth,
less developed countries
(LDCs).
4 Stages of the Demographic
Transition Model (continued)
3) Late Expanding:
Birth rate drops in response to high
growth of stage 2, death rate
continues to drop slowly, improved
standard of living & change in
societal values, birth control
improved, women join the labour
force, more urban nation (less
rural), more manufacturing &
industry, smaller families, total
population growth is moderate and
lowering.
4) Zero Growth:
Low birth & death rates, good
medical & health conditions, long
life expectancy, high standard of
living, little population growth
occurs-approaching zero
population growth rate/ negative
population growth, more developed
countries (MDCs).
Population Pyramid Activity
Canada’s Dependency Ratio in
2006

Young dependants = young males (2.7% + 2.9% + 3.4%) + young females (2.6%
+ 2.8% + 3.2%) = 17.6%

Old dependants =
old males (1.9% + 1.6% + 1.2% + 0.8% + 0.5%) + old females
(2% + 1.8% +1.6% + 1.3% + 1.1%)

People of working age =

Dependency ratio =
= 13.8%
100% - (17.6% + 13.8%)
= 68.6%
YD (%) + OD (%)
People of working age (%)
x 100
Canada’s Dependency Ratio for 2006 =
( (17.6% + 13.8%)/ 68.6% ) x 100 = 45.8 per 100 workers

Canada is in Stage 4 of the
Demographic Transition Model
Because:
Low birth & death rates
Good medical & health conditions
Long life expectancy
High standard of living
Little / negative population growth occurs
More developed country (MDC).
Animated Canadian
Population Pyramids
http://www12.statcan.ca/censusrecensement/2006/as-sa/97551/tables-tableaux-noteseng.cfm#animations
Population Pyramids of
the World
http://populationpyramid.net/
Review
Population Pyramids
 3 Types
 Dependency Ratio
 Demographic Transition Model
 4 (or 5) Stages of the Demographic
Transition Model
