Demographic Transition Theory in its original form was propounded by Warren Thompson and Frank Wallace Notestein. The theory postulates of a special pattern of demographic transformation high fertility and high mortality to low fertility and low mortality, when society progresses from a dominantly rural, agrarian and illiterate society to a predominantly urban, industrial and literate society.
These changes occur in stages which are collectively known as a Demographic Cycle. Demographic transition theory can be used to describe and predict the future population of an area.
Stages of Demographic Transition:
Five stages of demographic transition are recognized based on changing patterns of the birth and death rate.
Stage l. High Stationary Stage:
- It is the initial stage of demographic transition in which the fertility (birth rate) is over 35 per thousand and is almost stable. In this stage, the mortality (death rate) is also high being more than 35 per thousand but its behavior is erratic because of the epidemics and variable food supply. In this stage, the population is often stable or slowly growing and the people are engaged in primary activities.
- This is the characteristic of agrarian societies where the density of population is low and moderate, productivity level is low, life expectancy is low, people in masses are illiterate, the development of the non-agricultural sector is at its infancy stage and urban development is limited.
- About 200 years ago, all the countries of the world are at this initial stage of demographic transition but today it is difficult to say whether any country in the world would still be at this stage of the demographic transition mainly due to the spread of modern technology and the facilities of medicines even in the most backward countries.
- Because of this, it is very difficult to find a solitary example of a country which may still be affected by the process of declining mortality all over the world.
- Exceptionally some limited areas in equatorial (tropical) Africa may be traced which may be in the high stationary stage of demographic transition.
Stage ll. Early Expanding Stage:
- This is the second stage of demographic transition which is characterized by a high birth rate of over 35 per thousand and a sharply reduce the death rate of over 15 per thousand. In this expanding stage of demographic transition, the improvements in sanitation and health conditions, general productivity, etc. results in sharp decline in the death (mortality) rates, while the fertility maintains a high level.
- Thus, high fertility and declining mortality are the main characteristics of the early expanding stage. In this stage, the population expands at a gradually increasing rate.
- Afghanistan, Iran, Iraq, Nepal, Myanmar, Bangladesh and Pakistan in Asia and Angola, Ethiopia, Ghana, Morocco, Sudan, Congo Democratic Republic, Nigeria, Uganda, Tanzania and Kenya in Africa are included in this category.
Stage lll. Late Expanding Stage:
- Slowly declining fertility and sharply declining mortality is the main characteristic of late expanding stage of demographic transition. It is also characterized by a slowing in the growth rate because the death rate stabilized at a low level (below 15 per thousand) and declining birth rate stands over 20 per thousand. This decline is associated with the growth of an industrial and urban society.
- In this stage, the process of industrialization, urbanization, and modernization become prominent and large families are no longer an asset.
- Consequently, the birth rate undergoes a gradual decline leading to a gradual decrease in the rate of population increase. The countries in this stage experienced a high net increase in India population.
- The examples of the countries in the late expanding stage are Egypt and South Africa in Africa; India, Sri Lanka, Philippines, Indonesia, Malaysia, Thailand, Turkey, etc. in Asia and Brazil, Argentina, Chile, Peru, Venezuela, Mexico, etc. in Latin America.
Stage lV. Low Stationary Stage:
- This is the last stage in the demographic transition which is attained when both fertility and mortality rates decline appreciably.
- In this stage of the population is either stable or grows very slowly. Although the population grows slowly both in the first (high stationary) and the last (low stationary) stage, yet there is the product of contrastingly different situations.
- Whereas the slow growth of population or stable population in the first stage is the product of high fertility rate and high mortality rate, the stationary population or slow increase in population in the last stage of demographic transition is the result of low fertility and low mortality rates.
- In the first stage, the rate of fertility (birth rate) is high and about stable, and mortality is high but fluctuating while in the fourth stage, the mortality is low and stable and fertility is low but fluctuating.
- In the low stationary stage, the population is highly urbanized and socio-economically advanced.
- In this stage the family size is usually small, the literacy and educational levels are high, the labor is much skilled and specialized, per capita income is high causing high living standards.
- Developed countries of Europe and Anglo-America, Australia, New Zealand, Japan, Russia, etc. are supposed to have reached the low stationary stage of demographic transition.
- China recently has entered this stage when it succeeded in bringing down its birth rate and death rate drastically. Its achievements in the lowering of its natural rate of increase to a level of advanced countries in a very short time are appreciable.
Stage V. Declining Stage:
- The original Demographic Transition Theory has just four stages, but additional stages have been proposed.
- In this stage, birth rates fall below death rates to give a declining population. Some evidence suggests that this might be occurring in several western European countries.