Population Pyramids Lecture Notes

What is a Population Pyramid?

A population pyramid is a graph that shows the age and sex distribution of a population in a specific area (city, country, continent, etc.).
It consists of two bar graphs:
- Left bar graph: Represents the male population.
- Right bar graph: Represents the female population.
Y-axis: Displays ages in 5-year increments.
X-axis: Displays the percentage of the population each bar represents.
Example: Males aged 0-4 may make up 9% of the total population.

Population pyramids can be categorized into three main types:

Characteristic: Population is growing, with each new generation larger than the previous.
Example: Chad
- High birth rates: Women have more babies at younger ages.
- Large young population: Nearly half of Chad’s population is under 15.
- Shorter life expectancy: Many do not live past 65 due to poverty issues (lack of food, water, healthcare).
Common in developing countries (Africa, parts of Asia, South America).

Characteristic: Population is stable; not much growth.
Example: United States
- Population is consistent across age groups.
- Lower birth rates: Women have fewer children at older ages due to better access to education and employment.
- Longer life expectancy: Access to food, water, healthcare.

Characteristic: Population is constricted at the bottom.
Example: Italy
- Lower birth rates resulting in an older population.
- Good access to resources: Better healthcare, education, leading to higher life expectancy.

Example: Qatar and Saudi Arabia
- Unusual shapes due to large numbers of immigrant workers, mostly men, in oil and gas industries.
- Referred humorously as a "population woodpecker."

Population pyramids provide insights into the demographic makeup of a region.
The shape of the pyramid reveals information about birth rates, death rates, and life expectancy.
Different regions exhibit different pyramid shapes based on their socio-economic conditions.