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