Population composition refers to the structure of a population in terms of age, sex, literacy, occupation, marital status, religion, language and other social and economic characteristics. The composition of a population tells us how many people are in which age group, how the sexes are balanced, and what proportion of the people work in agriculture, industry or services. These characteristics help planners and governments design policies for education, health, housing and employment.
Every society has a unique population structure that changes over time. A population with many young people needs more schools and job creation, while a population with many elderly people needs more pension, health and old-age care services. Studying population composition therefore helps in understanding the social and economic condition of a country and in predicting its future needs.
The sex composition of a population is measured by the sex ratio, which is the number of females per thousand males in the population. A balanced sex ratio of around 1000 or slightly above is considered healthy. In many parts of the world, especially in South and East Asia, the sex ratio is lower than 1000, indicating fewer females than males. In contrast, many European countries have a sex ratio above 1000 because females generally outlive males.
The sex ratio is influenced by several factors, including the biological advantage of females in longevity, sex-selective practices, migration of male workers, differences in mortality between boys and girls, and social discrimination. In India, the sex ratio has historically been unfavourable to females, though it has shown improvement in recent censuses. The sex ratio is one of the most sensitive indicators of the status of women in a society.
The age structure of a population is the proportion of people in different age groups. Demographers usually divide the population into three broad groups: children (below 15 years), adults in the working age group (15 to 59 or 15 to 64 years), and the aged (60 or 65 years and above). The share of these groups is expressed as the age dependency ratio, which shows the number of dependents (children and aged) for every hundred persons in the working age group.
A country with a large share of children has a high dependency ratio and needs heavy investment in education and health, while a country with a large elderly population faces the challenge of providing pensions and medical care. A country with a large working-age population enjoys a "demographic dividend" because a smaller proportion of people are dependents. The age structure is the most important determinant of the future size and needs of a population.
The age-sex pyramid is a graphical representation of the age and sex structure of a population. It consists of two back-to-back bar graphs, one for males and one for females, with the youngest age group at the base and the oldest at the top. The shape of the pyramid reveals a great deal about the population's history, its birth and death rates, and its stage in the demographic transition.
A pyramid with a broad base and narrow top, like a triangle, indicates a high birth rate and high growth, typical of developing countries such as India and Nigeria; this is an expanding population. A bell-shaped pyramid indicates a stationary or slowly growing population with moderate birth and death rates, typical of some developed countries. A narrow base and broad top, like an urn shape, indicates a declining population, typical of countries like Japan and Germany where birth rates are very low and the elderly form a large share.
The rural-urban composition of a population shows the proportion of people living in villages and towns. This composition depends on the level of economic development, the growth of industries and the degree of urbanisation. Developed countries generally have a high proportion of urban population, often exceeding 75 per cent, while developing countries still have a majority of their people living in rural areas.
Urban population grows both through natural increase and through rural-to-urban migration. The level of urbanisation is an important indicator of economic development because cities are centres of industry, trade, services and innovation. However, rapid and uncontrolled urbanisation can create problems such as slums, unemployment, pollution and pressure on civic amenities, which many developing countries face today.
The occupational structure refers to the distribution of the working population among primary, secondary and tertiary activities. Primary activities such as agriculture, fishing and mining are concentrated in developing countries, where a large share of the labour force depends on farming. Secondary activities such as manufacturing and construction, and tertiary activities such as trade, transport and services, dominate the economies of developed countries.
The shift of workers from primary to secondary and tertiary activities is called the occupational shift or structural transformation and is a sign of economic progress. In India, although the share of agriculture in the national income has fallen, a large proportion of the workforce is still engaged in agriculture, a feature called overpopulation of the primary sector. The occupational structure therefore reflects the stage of economic development of a country.
Literacy is an important component of population composition because it reflects the quality of human resources. Literacy rate is defined as the percentage of people aged seven years and above who can read and write with understanding. Developed countries have literacy rates close to 100 per cent, while many developing countries still struggle to achieve universal literacy, especially among women and in rural areas.
Education determines the skills of a population and its ability to adopt new technologies. Higher female literacy is associated with lower fertility, better health and higher standards of living. In India, the literacy rate has improved steadily since independence, and the gender gap in literacy is also narrowing, though significant regional variations remain. Literacy is thus both a cause and an effect of social and economic development.
| Shape of Pyramid | Type of Population | Growth | Example Countries |
|---|---|---|---|
| Triangular (broad base) | Expanding | High birth rate, rapid growth | India, Nigeria, Bangladesh |
| Bell-shaped | Stationary | Moderate birth and death rates | United States, France |
| Urn-shaped (narrow base) | Declining | Very low birth rate, ageing | Japan, Germany, Italy |
| Component | Indicator | Significance |
|---|---|---|
| Sex Composition | Sex ratio (females per 1000 males) | Status of women in society |
| Age Structure | Proportion in 0-14, 15-59, 60+ groups | Dependency ratio, demographic dividend |
| Rural-Urban | Urbanisation level | Stage of economic development |
| Occupational | Share in primary/secondary/tertiary | Structural transformation of economy |
| Literacy | Literacy rate (7+ years) | Quality of human resources |
Population composition describes the structure of a society in terms of its sex ratio, age structure, rural-urban distribution, occupation and literacy. The age-sex pyramid provides an excellent visual summary of a population's history and its position in the demographic transition, with triangular, bell-shaped and urn-shaped forms indicating expanding, stationary and declining populations respectively. The dependency ratio and the occupational structure reveal the economic pressures and the stage of development of a country. Literacy, especially female literacy, remains the key to improving the quality of human resources. Together, these components give a complete picture of a society and guide planners in meeting the needs of their people.
Keywords: Population composition, sex ratio, age structure, age-sex pyramid, dependency ratio, occupational structure, literacy rate.