Population composition: definition and factors


Population refers to people living and interacting in a particular area or region. It is a very important factor for geographical boundaries. The population can not remain stable due to birth rate, death rate, migration, etc and therefore the concept of population is highly dynamic. Thus the population composition depends upon some important factors.

From ancient times to the present time, the characteristics of the population in different countries of the world have changed. The population composition of a place can be clearly explained by the characteristics of the population. Population geography studies population composition based on various factors such as age, sex, religion, language, economy, etc. (1) & (4).

Population composition

The factors that make up or influence the population of a country together are called population composition. Population composition refers to the age and gender of the population of a country or region. An increase in the birth rate of a country means an increase in the size of the child population.

When the birth rate decreases, the amount of child population decreases. The structure of the working population, child population, old population, etc. is known by population composition. Population composition can be determined accurately by dividing the population by male or female or by dividing the population by different ages (4).

Interesting features

  • Population composition helps in comparison between the populations of different places.
  • The study of population composition explores human resources.
  • This gives an accurate idea of birth and mortality rates.
  • Its structure gives an idea of various social and economic issues.
  • Population composition describes the characteristics of population distribution that are changed by spatial factors (4).

Population composition factors

The composition of the population depends mainly on four factors. These are

1. Age composition

The first factor of population composition is age structure. This means the proportion of the population in a population of different age ratios. The population composition of a country depends a lot on its age-based structure. Total production will decrease in a country with a large population and a proportion of people under 15 and over 60.

In developed countries, the rate of population growth is quite low and the life expectancy of these countries is high due to improved services. As a result, the proportion of the population under the age of 15 is lower in these countries. However, the proportion of the population above the age of 6 is higher due to longer life expectancy and lower overall population growth (2).

Age-sex pyramid

The age-based composition of the population is usually described with the help of the age-sex pyramid. A diagram that shows the size and influence of a country’s population of different ages between men and women is called the age-sex pyramid. One can get an idea about the speed of population growth, type of female population, birth and death rate, etc. from this pyramid.


  • The structure of the population pyramid reflects the characteristics of the population.
  • Population pyramid shows the number or percentage of males and females along the ‘X’ axis of the pyramid structure and the age along the ‘Y’ axis.
  • The y-axis shows the age of men on the left and the age of women on the right.
  • If the horizontal surface of a country’s population pyramid is wide, then the total population of that country is more than the number of children or young people.
  • The middle part of the population pyramid of developed countries swells. And the middle part of the population pyramid of developing countries is narrow.
  • Population composition of a country is determined by the population pyramid.


  • The age-sex pyramid gives an idea of the level of evolution.
  • From this pyramid, it is possible to understand the differences in the age-based format of men and women.
  • It describes the concept of dependency ratio.
  • The socio-economic situation of a country or a region can be estimated by an age-sex pyramid.
  • It gives an idea about the birth rate, mortality rate, and population growth rate (3).

2. Sex composition


The ratio between the number of men and women in the population is known as the sex ratio.


  • The sex ratio of women to men in a country’s population is an important factor.
  • In the case of developed countries, men, as well as women, need to be equally involved in the development of the country. This is seen in developed countries.
  • But in developing and underdeveloped countries women do not have equal rights with men. That is why women are unproductive.
  • Immigration is one of the main causes of the difference in the sex ratio of a country.
  • If the value of the sex ratio is low, it indicates underdeveloped socio-economic status.
  • The sex ratio changes over time.
  • In underdeveloped and developing countries, the sex ratio is higher in villages than in cities (2) & (3).


1. Initial sex ratio

It indicates the ratio of males to females during pregnancy.

2. Secondary sex ratio

The ratio of males to females at birth is called the secondary sex ratio.

3. Tertiary sex ratio

The sex ratio that exists during the census is known as the tertiary sex ratio.

Determination method

  • The formula for determining the sex ratio based on the number of females per thousand males in India is-

Sex ratio = Total female population/ total male population * 1000.

  • The formula for determining the sex ratio based on the number of males per 100 females in the United States is-

Sex ratio = Total male population/ total female population* 100 (2) & (3).

3. Literacy rate

Literacy means the ability to recognize letters, write, and read. If a person reads a subject and is able to express it in writing, then he is called a literate person.


  • The proportion of a country’s educated population is an indicator of its socio-economic development.
  • Literacy rate reflects the quality of life, social status of women, educational opportunities, and government policies.
  • In India, literacy rate refers to the percentage of the population over the age of 7 who have the ability to read, write and perform mathematical calculations (2).

4. Economic structure

  • Economic structure refers to the type of economic activity associated with the population of a country.
  • In underdeveloped countries agriculture is the main source of livelihood and alternatives to agriculture have not been properly developed.
  • In developing and developed countries there are various types of occupations such as forestry, fishing, manufacturing, construction, commercial transport, etc.
  • The population composition is formed based on all these occupations (1) & (3).

5. Ethnic composition

Another important factor is ethnic composition. There are basically five ethnic groups in the world. They are Caucasians, Negroes, Mongoloids, Australoid, and American Indian. Their role in population composition is quite important.

Each ethnic group has its own characteristics that set them apart from each other. Skin color, height, brain shape, face color, hair color, body structure, etc. are different from each other. So the population composition of each country is different based on the ethnic composition (4).


1. What is the study of the size, composition, growth, and distribution of the human population?

The study of the size, composition, growth, and distribution of the human population is demography.

2. Why does population composition matter?

Population composition means the structure of the population. It is formed according to the age composition, sex ratio, economic composition age-sex pyramid.

3. A demographer is a specialist who studies the size, composition, and distribution of a population.

The statement is true.

4. What is the population composition of 20 who lives in Darfur (population, ethnic, religious, occupational composition)?

The factors that influence the population structure of a country together are called population composition.

Arabs, Beja, Zaghawa, Nubian, and Daju peoples lived in Darfur.

Written By: Manisha Bharati

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