POPULATION

STRUCTURE

The interpretation of age / sex pyramids

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.

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.

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

Comparing LEDC & MEDC

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

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.

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

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

The population pyramid for the USA:

Is similar to that of USA

It represents a zero-population growth

(BR – DR = 0)

People are distribute evenly throughout the cohorts

The population pyramid for Germany:

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

Implication of this type of population structure

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

Advantages of ageing population

Tourism sector is boosted by the elderly taking holidays during off-peak seasons

Industries that tap into the pensioner market (e.g. wheel chairs)

Some large properties have been converted to profitable residential homes

Dependency ratio

Dependency ratio = % of population aged 0-15 + % of population aged 65+

% 0f population of working age