Demography’s defined as the study of a population or populations, particularly with reference to size and density, fertility, mortality, growth, age distribution, migration, and the interaction of all of these with social and environmental conditions.
As regard definition of this term, the economists, geographer’s, social scientists and others have defines it in their own way as that suits their viewpoint. Some important definitions are given below:
Frank Lorimar-” In broad sense demography includes both demographic analysis and population studies. A broad study of demography studies both qualitative and quantitative aspects of population.”
Benard Benjamin-“ The demographer is concerned with measuring past and forecasting future population change. To do so he must isolate and quantify not only the principal of fertility, mortality and migration but also the underlying factors concerned in these elements for example social and economic influences at work”.
Irene Tanker-“ With improved data, new techniques and precise measurement of the demographic transition that is occurring demography has become science rather than literature.”
Demography is the size of population and in its most general meaning, a population is a set of people who live in a specific land area: a district, country or a continent. The scope of demography is very wide. It includes the subject matter of demography, whether it is a micro or macro study. Whether it is a science or art.
Population studies are also useful for administrators who run the government. In under-developed countries, almost all social and economic problems are associated with the growth of population. The administrator has to tackle and find solutions to the problems arising from the growth of population. They are migration and urbanization which lead to the coming up of shanty towns, pollution, drainage, water, electricity, transport, etc. in cities.
These require improvement of environmental sanitation, removal of stagnant and polluted water, slum clearance, better housing, efficient transport system, clean water supply, better sewerage facilities, control of communicable diseases, provision of medical and health services, especially in maternal and child welfare by opening health centers, opening of schools, etc.
The knowledge of demography is of immense importance for a democratic political system. It is on the basis of the census figures pertaining to different areas that the demarcation of constituencies is done by the election commission of a country. The addition to the number of voters after each election helps to find out how many have migrated from other places and regions of the country.
Political parties are able to find out from the census data the number of male and female voters, their level of education, their age structure, their level of earning, etc. On these basis, political parties can raise issues and promise solutions in their election manifestos at the time of elections.