Page 13 - Health, Population and Environment Education 10

2.1 Demographic Components, Process and Measurement
People live in different places. Some places have more population and some have less
population. Population is studied under demography. Demography is made up of two
Greek words demos which means people or population and ‘graphien’ which means
study. In simple words, demography is the study of population. Demography is the
scientific, mathematical and statistical study of population in relation to population size,
structure, density, distribution, composition, etc.

The word ‘demography’ was first coined by a Belgian, Achille Guillard in his famous
book called ‘Comparative Demography’ in 1855 A.D. But the demographic study was
first conducted by John Graunt who is also regarded as ‘Father of Demography’. He
published a book “Natural and Political Observation” in 1662 A.D. in which he analyzed
the statistics on deaths of people (Bills of Mortality) in London.
Population is dynamic in nature. It keeps on changing time and again. It never remains
constant. Birth, death and migration are actually responsible for change of population.
With the variation in all of them, population also keeps on changing.

The following table shows demographic components, processes and measurements:
Demographic Components Demographic Processes Demographic Measurements
Birth Fertility Fertility Rate
Death Mortality Mortality Rate
Migration Migration Migration Rate

Demographic Components
Those elements which are responsible for change of population in a place are called as
demographic components. Birth, death and migration have direct impact on population
of a place. They are called demographic components. When there is birth of a child, there
is increase in the number of family members which results in the increase of population.
Once a person takes birth, sooner or later, he/she has to die. Death causes decrease
of population in a place. Migration can either increase or decrease the population.
Inmigration (internal migration) and immigration (international migration) increase the
population whereas out migration (internal migration) and emigration(international
migration) decrease the population of a place. Birth and death are natural factors of
population change and migration is artificial factor of population change.

Demographic Processes

The performance of demographic components is called demographic processes. Fertility,
mortality and migration are demographic processes. There is change of population with
all of them. Fertility is related with birth and increase of population. Mortality denotes
death and decreases population. Migration is related with national and international
migration which shows either increase or decrease of population. These demographic
processes either increase or decrease population in a place.

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