Population
Pyramids
Population Pyramids
Population Pyramids
A graphical representation of the age and
gender structure of a population.
Consists of 2 horizontal bar diagrams -- one for
the male and the other one for female.
Placed side by side according to the various
age groups (usually in a 5 year period).
Example Population Pyramid
Population Pyramids
INFORMATION POSSIBLE FROM
A POPULATION PYRAMID:
1. Age Structure
• young: < 16 years
• mature: 16 - 64
• aged: > 64
Population Pyramids
INFORMATION POSSIBLE FROM
A POPULATION PYRAMID:
2. Sex Ratio – female : male
3. Dependency Ratio:
young + aged
------------------------mature
Population Pyramids
INFORMATION POSSIBLE FROM
A POPULATION PYRAMID:
4. Birthrate from the base of the pyramid.
5. Life expectancy can be inferred.
6. Can infer economic status (for example, agriculture or
industrialized type of nation).
Population Pyramids
YOUNG POPULATION
M
F
Population Pyramids
CHARACTERISTICS OF
YOUNG POPULATION:
1. High birthrate.
2. High proportion of dependent population to
working population. Therefore, expect low
standard of living.
Population Pyramids
CHARACTERISTICS OF
YOUNG POPULATION:
3. Agricultural economy.
4. Problems associated with overpopulation.
Population Pyramids
MATURE POPULATION
M
F
Population Pyramids
MATURE POPULATION
CHARACTERISTICS OF
MATURE POPULATION:
1. Birthrate and death rate low -- about 1%
population growth.
2. High proportion working.
Population Pyramids
MATURE POPULATION
CHARACTERISTICS OF
MATURE POPULATION:
3. industrialized nation = high living standard
Population Pyramids
AGING POPULATION
M
F
Population Pyramids
AGING POPULATION
CHARACTERISTICS OF
AGING POPULATION:
1. Very low birthrate, so a low or zero population
growth.
2. Many aged dependents.
Population Pyramids
AGING POPULATION
CHARACTERISTICS OF
AGING POPULATION:
3. Advanced industrialized country (for example, UK,
Germany, Sweden, and Japan).
Importance of Population Pyramids
1. Enable comparisons to be made between countries.
2. Can help to plan for future service needs such as old
folk’s home if it has an aging population or build
fewer schools.
Importance of Population Pyramids
A BROAD BASE POPULATION
PYRAMID MEANS:
1. Increase food production.
2. Build more homes and schools.
Importance of Population Pyramids
A BROAD BASE POPULATION
PYRAMID MEANS:
3. Plan for more job opportunities for the young in future.
4. Implement birth control campaigns.
Importance of Population Pyramids
A NARROW BASED POPULATION
PYRAMID MEANS:
1. Work out incentives to encourage more births.
2. Hiring foreign labor.
3. Proper medical services and health care for the aged.
Some Population Pyramids
Some Population Pyramids
Some Population Pyramids
Some Population Pyramids
Population Pyramid of a Less Developed Nation
Population Pyramid of Nigeria (1995)
Population Pyramid of a Developed Nation
Population Pyramid of Sweden (1995)
POPULATION STRUCTURE
The population pyramid displays the age
and sex structure of a country or given area.
OLD DEPENDENTS
Population in
Five Year
Age bands
MALES
To the left
ECONOMICALLY
ACTIVE
YOUNG
DEPENDENTS
FEMALES
To the right
What Population Pyramids Show Us
Economically
More
Developed
Country
Economically
Less
Developed
Country
KEY
slope of pyramid indicate the death rate
width of the base is related to birth rate/fertility rate
proportions of men and women can suggest male or female migrations
height of graph can indicate life expectancy (ignore the very thin end of the
wedge as occurs on graph B as these people are a definite minority)
"kinks" indicate dramatic reductions in birth rate or increases in
death rate in the past
area of graph indicates total population - compare areas of different
population age groups or different sex on one graph
The overall shape of the population pyramid can indicate whether it is an
Economically More Developed Country or Economically Less Developed Country.
Population Pyramids Related to the
Demographic Transition Model
Stage 1
Stage 2
Stage 3
Stage 4
IMPLICATIONS
IMPLICATIONS
IMPLICATIONS
IMPLICATIONS
Both birth rates and
death rates are
high, so population
growth rates are
slow but population
is usually restored
due to high birth
rate. Short life
expectancy.
Population starts
to grow at an
exponential rate due to
fall in death rate. More
living In middle age.
Life expectancy rises.
Infant mortality rate falls.
Population continues
to grow but at slower
rate. Low death rate.
Dramatically
declining birth
rate.
Low birth rate and death
rate. Higher dependency
ratio and longer life
expectancy. Death rate
does rise slightly because
of the aging population.