THEORY OF DEMOGRAPHIC TRANSITON

Human being are both ends and means  for economic activities. when in right numbers they are an asset but not so in fact a reality if the numbers is beyond the capacity, the economy population is essential requisite for the study of population. No economy can be imagined without population. It will be useful to study India's population growth in the format of the theory of demographic transition. The Demographic Transition is the relationship between birth rate and death rate. The birth rate and death rate difference in different stages of economy development. Hence the growth rate of population also different.

The continuous economic development in economy has been creating a serious impact on its rate of growth of populations. A country has to proceed through different stages of population growth as the relationship between birth and death rates changes with economic development. C.P.Blacker has divided the population growth into five different types.

1. The high stationary
2. The early expanding
3. Late expanding 
4. The low stationary
5. The decline stage

Sax has divided the Demographic transition into four different stages. The theory of demographic transition mentions four different stages of change in birth and death rate in connection with economic development.

Stage 1 In this stage a country subjected to both high birth rate and death rate  at the first stage of an agrarian economy. The birth rate is very high due to universal and early marriage, wide spread prevalence of illiteracy, traditional social beliefs and customs, absence of knowledge about family planning, attitude towards children for supplementary family income etc.

In this stage the death rate is also high due to insufficient diets and absence of adequate medical and sanitation facilities. Besides no special arrangement for cleanliness. Famines and epidemics stall the land which also cause a high death rate.

Thus the first stage of Demographic transition is characterized by high death rate and high birth rate. Therefore the growth rate of population is more or less the same. Before 1921, India's population was in this stage.

Stage 2 With the gradual attainment of economic development, the living condition of people started to improve due to better and regular diet, better medical and sanitation facilities leading to fall in the death rate. Regular food supply, improved law and order situations, medical innovations and advancement of development of antibiotics, vaccines, and introduction of immunization programmes have led to substantial reduction in the incidence of disease and death.

At the stage, the birth rate continue to remain very hing in spite  of substantial fall in death rates, leading to accelerated growth of population.

Stage 3 With the attainment of economic development, the economy of the country started to experience a change in its structure from a agrarian to an industrialized one. During this stage people are conscious about their size of the family. In order to avoid the threat of large family people started to raise the age of marriage by postponing marriage as well as to limit reproduction. One of the features of economic development is typically increasing urbanization and children are usually more of a burden and less of an asset in an urban setting than in a rural.

Thus in this stage, the country will experiencing the fall in the birth rate, low death rate and consequently the fall in the rate of growth of population.

Stage 4 The fourth stage of demographic transition is characterized by a low birth rate and a low death rate of population, leading to a stationary population. It is therefore, known as the stage of stationary population where both the birth rate and death rate remain at a low level leading to a very little growth in population. During this stage, a significant change in social outlook of the people has taken place under the impact of urbanization, industrialization and high rate of literacy. Population becomes stationary at a  low rate.