Demographic Components

In this chapter, we discuss about the concepts of demographic components and basic demographic measurement. Reference Notes of Grade 8 Social Studies.

Demographic Components

Population change results from the interaction of demographic components: birth, death and migration. Therefore, demography deals with the detailed study of the three components. With the measurement of such components, various aspects of the population are analyzed and interpreted. It helps to plan and implement various development activities. Birth, death and migration are called demographic component, as well as the determining elements of population change because they affect the situation of the population. Therefore, the size of the population depends mainly upon birth, death and migration.

Fertility

Birth is an important component mainly related to fertility in the study of population education. Fertility deals with the birth. The population growth of a place/country depends upon fertility because the country with high level of fertility has a rapid growth of population. Fertility refers to the reproductive function. It is the ability to bear offspring. It is the production of live birth which starts when a woman gives the first birth. Its period is generally 15-49 years of age. Likewise, fecundity is the physical capacity to participate in reproduction. It starts with the regulation of monthly menstrual cycle. Fertility results in the birth. It is measured by the actual number of births.

Mortality

According to WHO, "Death is the permanent disappearance of all evidence of life at any time after birth has taken place." It is a natural process. The process of birth and death goes on incessantly. People die at different ages for different reasons. People die of different diseases and in several accidents. This is a perpetual process. This process causes the decline in population.

Migration

Migration means the movements of people from place to place. The movement of people inside the country is called national migration like Bhaktapur to Kathmandu. And the movement of people from one country to another is called international migration like Nepal to China.

The people who shift from the original place are called out-migrants and those people who live in their destination called in-migrants. In the same way, people who shift from one country to another are called emigrants for departure and immigrants for the destination. The difference in the number of people due to immigration and emigration in a country is called gross migration.

Measures of Population Change are:

Demographic measures are the actual changes in size, composition and distribution due to changes in demographic components like birth, death and migration, as a result of their respective processes like rate of fertility, mortality and migration. Demographic measures are enumerated by applying specific formulas for a specific type of measurement.

Fertility Rate

Fertility refers to the reproductive function. It is the ability to bear offspring. It is the production of live birth which starts when a woman gives the first birth. Its period is generally 15-49 years of age. Likewise, fecundity is the psychological capacity to participate in reproduction. It starts with the regulation of monthly menstrual cycle. Fertility results in a birth. It is measured by the actual number of births. The measures that are used to estimate fertility rate are as follows: -

1. Crude Birth Rate(CBR)

Crude Birth Rate is the simplest way of measuring fertility. The crude birth rate of an area is defined as the number of live births occurring in that area, in a given period of time, usually a year, divided by the total population of that area as estimated in the middle of the year. The rate is expressed in terms of 'per 1000 of the population'.

2. Age-Specific Fertility Rate(ASFR)

Fertility rates may be computed for each age from 15-49 years. However, computation of each year may not be necessary, generally fertility rates for five-year age groups are measured. Such fertility rates are known as age-specific fertility rate.

3. Total Fertility Rate(TFR)

Total fertility rate is referred to the number of children of women, would bear during her childbearing age under ongoing age-specific fertility rate (ASFR). It is measured as the sum of age-specific fertility rates calculated for the same single year. Since, the ASFR is calculated for 5 year age groups, the sum of ASFR’s need to be multiplied by 5.