What is a population pyramid?

A population pyramid refers to the graphical representation of population composition in a country. It is also called an age-sex pyramid as it diagrammatically presents the number of males and females in a country according to their age groups. In a population pyramid, the total population is divided into various age groups, e.g. 5 to 9 years, 10 to 14 years, etc. For each age group, the percentage of the total population is subdivided into males and females. The population pyramid allows us to understand the population composition in a country as it shows us the number of dependents in a country along with the percentage that is economically active.

In general, three pyramid shapes exist in the world. Countries like Kenya, where both birth rates and death rates are high, have a pyramid which is broad at the base and rapidly narrows towards the top. Owing to lower levels of development, very few of the large number of births, reach adulthood or old age. Developing countries like India show a broad base in the younger age groups as the country has a high birth rate and more infants survive to adulthood with development in science and technology. Developed countries like Japan with lower birth rates have narrow bases and increasing number of dependents when compared to the growth in work force.