What is meaning of Age Structure of population describe in brief four main characteristis of age structure of the World population.

Explanation

Age structure reprceenta the number of people of different age groups. This is an important indicator of population composition.
Following are the four characteristics of age structure of age composition of the world population:
(i) Population composition: The age group 0-15 is called young population, 15-59 age group of working population and above 60 years represents an ageing population which require more expenditure on health care facilities.
(ii) Age-Sex Pyramid: The age-sex structure of the population refers to the number of females and males in different age- groups.
(iii) Expanding population: Nigeria, Bangladesh, Mexico, India and other developing and under developed countries of the world is having the characteristics of expanding population which have triangular shaped pyramid with a wide box. These have larger population in lower age groups due to high birth rate.
(iv) Constant population: The developed countries like Australia, has age sex pyramid of bell shaped and tapered towards the top. It shows birth and death rates are almost equal leading to near constant population.
(v) Declining population : The developed countries having low birth and death rates come under this category which showsthe pyramid of narrow base and a tapered top. The population growth in developed countries is usually zero or negative. Example, Japan, Britain, France, etc.