Theme 1 - 1.3 - Population Structure Flashcards
Define population structure.
The composition of a population, the most important elements of which are age and sex.
What is a population pyramid?
A bar chart arranged vertically that shows the distribution of a population by age and sex.
Define dependency ratio.
The ratio of the number of people under 15 and over 64 years to those 15-64 years of age.
What factors determine the structure of a population?
- Fertility
- Mortality
- Migration
What ages is the economically active population said to be at?
15-64 years
What are the most studied aspects of population structure?
Age and sex
Describe the population pyramid for a place in stage 1 of the DTM.
- Very wide base
- Narrows quickly with an inward curve.
(Diagram - Pg 14 of revision guide)
Describe the population pyramid for a country in stage 2 of the DTM.
- Wide base with gradual narrowing.
- Almost triangle shaped, although often curves inwards.
(Diagram - Pg 14 of revision guide)
Describe the population pyramid for a country in stage 3 of the DTM.
- Slightly narrower base than stage 3
- Narrows more gradually.
- Almost triangle shaped, although often curves slightly outwards near base.
(Diagram - Pg 14 of revision guide)
Describe the population pyramid for a country in stage 4 of the DTM.
- Narrow base
- Bulges outwards slightly near the middle-age section.
(Diagram - Pg 14 of revision guide)
Describe the population pyramid for a place in stage 5 of the DTM.
- Very narrow base
- Pyramid bulges outwards near the middle-age/elderly section
(Diagram - Pg 14 of revision guide)
Give reasons for the shape of the population pyramid of stage 1 regions.
- Wide base -> High birth rate
* Rapid fall in each age group above -> High death rate and short life expectancy
Give reasons for the shape of the population pyramid of stage 2 countries.
- Wide base -> High birth rate
* Gradual decrease -> Slightly lower death rate and slightly higher life expectancy
Give reasons for the shape of the population pyramid of stage 3 countries.
- Slightly narrower base -> Lower fertility due to governmental policies, etc.
- Gradual decrease -> Lower death rate and longer life expectancy
Give reasons for the shape of the population pyramid of stage 4 countries.
- Narrow base -> Low birth rate due to social norms and governmental policies, etc.
- Outwards bulge -> Many middle-aged due to low death rate and long life expectancy
Give reasons for the shape of the population pyramid of stage 5 regions.
- Very narrow base -> Very low birth rate
* High outwards bulge -> Low death rate and very long life expectancy
Are population structure pyramids the same for every part of a country?
No, they are usually significant differences between rural and urban areas.
How might urban areas differ from rural areas in terms of population structure within a country and why?
Rural
• Fewer young adults and children -> Out-migration of families to urban areas
Urban
• More young adults and children -> In-migration of families from rural areas
• More of a certain age or sex -> Due to selective migration
What is a good exam technique when describing and explaining a population pyramid?
- Divide the pyramid into three sections: young dependent population, economically active population and elderly population
- Comment on each section in turn
What are the implication of having a largely young population (e.g. Niger and Bangladesh)?
- Young people have to be housed, fed, educated and looked after in terms of health -> This costs the government money
- May result in child labour
- Pressure on services (e.g. Education)
What are the implication of having a largely elderly population (e.g. UK and Japan)?
- Elderly people have to be looked after in terms of health, wellbeing, etc. -> This cost the government money
- Pressure on services (e.g. healthcare)
Who are dependents?
People who are too young or too old to work.
What is the formula for calculating dependency ratio?
Dependency ratio = ((Population 14 and under + Population 65 and over) / Population aged 15-64) x 100
How do you calculate the dependency ratio of a country?
- Add the number of people under 15 and over 65 together
- Divide this by the number of people aged 15-64
- Multiply this by 100
What does a dependency ratio of 60 mean?
For every 100 people in the economically active population, there are 60 people dependent on them.
I.e. 100 economically active : 60 dependent
What is the dependency ratio usually around in more developed countries?
Between 50 and 75.
What is the dependency ratio usually around in less developed countries?
It can reach over 100.
Who forms the majority of the dependent population in more and less developed countries?
More developed: Children and the elderly
Less developed: Children
