The Theory of Demographic Transition
Demography is the study of the components of population variation and change. Death rate and birth rate are two determinants of population change. Theory of Demographic Transition is comparatively recent theory that has been accepted by several scholars throughout the world. This theory embraces the observation that all countries in the world go through different stages in the growth of population. A nation's economy and level of development is directly related to that nation's birth and death rates. Population history can be divided into different stages. Some of the scholars have divided it into three and some scholars have divided it into five stages. These stages or classifications demonstrate a transition from high birth and high death rates to low birth and low death rates. The Theory of Demographic Transition suggests that all nations begin in stage one as underdeveloped, third world nations and through time transition into first world nations. Firstly this theory was developed based on the statistic collected in many European countries. In this theory, birth rate and death rate are considered to be the major factors or demographic events for bringing change in population.
In the early 20th century, two demographers Landry and Warren Thompson tried to describe transition from the stage high birth rate and high death rate to low birth rate and low death rate. O.P. Walker has classified the `Theory of Demographic Transition' into five stages as follows (Raj, H. 2003):
The High Stationary Stage
The Early Expanding Stage
The Late Expanding Stage
The Low Stationary Stage
The Declining Stage
The High Stationary Stage:
This is the first stage of the theory of demographic transition. In this stage, the birth rate and death rate both are very high. But the death rate exceeds the birth rate, which triggers the population increasing very slowly or almost stable. In this stage, birth rate becomes high due to less use of contraception and sterilization. Most of the people do survive in agriculture where the children are considered as economic assets and so people are encouraged to get many children. Similarly death rate becomes high due to diseases, natural calamities, wars, etc. Infant death rate is also found very high. Because of poor health facilities provided by the state to the people, lack of clean water and sanitation and food shortage, health of the people will be weak so that the people will depart the life in high numbers. Before 1920, China and India were at this stage (Raj, H. 2003). This stage is generally found in the countries where people depend on agriculture as a main source of surviving. At present, the countries like Nigeria, Ethiopia, Tanzania, Angola, etc. are passing through this stage (Raj, H.2003)
The Early Expanding Stage:
This is the second stage of the Theory of Demographic Transition. In this stage, birth rate does not come down from the High...