Population pyramid
Also called: Age-sex pyramid · Topic: Measuring Development: Income, HDI and Sustainability · NCERT: Beyond NCERT
Meaning
A population pyramid is a bar graph of a population by age group and sex. Males are shown on one side and females on the other, with the youngest at the bottom. Its shape shows the stage of demographic transition, which is the shift from high births and deaths to low births and deaths. Planners use it to see whether a country will need more schools, more jobs or more elder care.
There are three main shapes:
- Expansive: wide base, high births.
- Constrictive: the base is narrowing because births are falling.
- Stationary: nearly straight sides, with low births and low deaths. This is typical of ageing societies.
Example
Pakistan, with a TFR of 3.4, has an expansive pyramid. India's pyramid is now constrictive, because its TFR has fallen to 2.0 (NFHS-5). Kerala and Tamil Nadu are ageing well ahead of Bihar and UP, so their pyramids are moving towards the stationary shape.
Don't confuse with
- Dependency ratio: this is one number, (0–14 + 65+) ÷ (15–64). A pyramid is a picture of the full age–sex structure.
Related concepts
- Population growth rate
- Population density
- Sex ratio
- Son preference
- Total fertility rate
- Replacement level fertility
- Urbanisation
- Dependency ratio
- Demographic window of opportunity
- Ageing population