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.

Population in

Five Year

Age bands

OLD DEPENDENTS

ECONOMICALLY ACTIVE

YOUNG

DEPENDENTS

FEMALES

To the right MALES

To the left

What Population Pyramids Show Us

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.

Economically

More

Developed

Country

Economically

Less

Developed

Country

Population Pyramids Related to the

Demographic Transition Model

Stage 1 Stage 2 Stage 3 Stage 4

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.

IMPLICATIONS

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.

IMPLICATIONS

Population continues

to grow but at slower

rate. Low death rate.

Dramatically

declining birth

rate.

IMPLICATIONS

Low birth rate and death

rate. Higher dependency

ratio and longer life

expectancy. Death rate

does rise slightly because

of the aging population.