Population Pyramids
What is a Population Pyramid?
A population pyramid is a type of graph that is used to illustrate a population’s age and sex structure. It is also called an age-sex pyramid.
Population Pyramids are based on natural change (births-deaths) only – it does not include the effects of migration.
A population pyramid is a simple graph that conveys the complex social narrative of a population through its shape. Examining the population in a single year can allow us to:
Population Pyramids are based on natural change (births-deaths) only – it does not include the effects of migration.
A population pyramid is a simple graph that conveys the complex social narrative of a population through its shape. Examining the population in a single year can allow us to:
- see what stage the country is in
- see a record of its past
- predict future population trends
- make predictions about the types of services that population will need e.g. schools, aged-care homes.
Interpreting Population Pyramids
Population pyramids show the structure of a population by comparing relative numbers of people in different age groups called 'age cohorts'.
Population Pyramids: Powerful Predictors of the Future
By Kim Preshoff and TED-Ed [5:01] Description: Population statistics are like crystal balls - when examined closely, they can help predict a country's future (and give important clues about the past). Kim Preshoff explains how using a visual tool called a population pyramid helps policymakers and social scientists make sense of the statistics, using three different countries' pyramids as examples. |
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Population Groupings
Reproductive years
These groupings are used to predict future populations:
The age divisions between reproductive groupings are not hardline rules. Girls 14 years old and younger, and women over the age of 45, can and do bear children. And some women between the ages of 15 and 44 years old are not able to bear children. These groupings are based on averages of the ages at which most females are at the height of their fertility.
These groupings are used to predict future populations:
- 0-14 years: Pre-reproductive years
- 15-49* years: Reproductive years
- 50+ years: Post-reproductive years
The age divisions between reproductive groupings are not hardline rules. Girls 14 years old and younger, and women over the age of 45, can and do bear children. And some women between the ages of 15 and 44 years old are not able to bear children. These groupings are based on averages of the ages at which most females are at the height of their fertility.
Working-age and dependents
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Population Growth Categories
The demographic characteristics of countries can be divided into three broad categories:
- Expansive (young and growing)
- Stationary (little or no population growth)
- Contractive or constrictive (elderly and shrinking)
Stages
Note: The numbers 15 and 65 on each pyramid refer to ages. They separate the pyramid into:
- elderly dependents (65 years and over) - orange
- working-age population (15-64 years) - royal blue
- young dependents (0-14 year olds) - light blue
Stage 1: High Stationary
Stage 2: Early Expanding
Stage 3: Late Expanding
Stage 4: Low Stationary
Birth and death rates are both low, stabilising the population.
These countries tend to have stronger economies, higher levels of education, better healthcare, a higher proportion of working women, and a fertility rate hovering around two children per woman (replacement rate is 2.1) Most developed countries are in Stage 4. |
Stage 5: Contracting (aka declining)
Demographic Transition Model (DTM)
Each of the 5 stages below in the Demographic Transition Model correspond with the stages of the population pyramid shapes shown above.
Country Examples
Note: On the x axis which shows population size, the numbers will change depending on the country's population size
e.g. Syria has intervals of 500,000 people, while China has intervals of 20 million people.
e.g. Syria has intervals of 500,000 people, while China has intervals of 20 million people.
Source: Countries - The World Factbook (cia.gov) > Country > People and Society > Population Pyramid
Population Pyramid Simulators
Population Pyramid Simulator
By the INED (Institut National d’Etudes Démographiques) Click on ‘Free Simulation’ > ‘Start Simulation’ |