Explain the Demographic Transition Theory.

Answer: Demographic Transition Theory

The Demographic Transition Theory explains how the population of a region changes over time as the society moves from a rural, agrarian, illiterate stage to an urban, industrial, literate stage, through changes in birth rate and death rate. It was proposed by Warren Thompson (1929) and developed by Frank Notestein. It has the following stages (often shown as a graph of birth rate, death rate and total population against time):

1. Stage I – High stationary: both birth rate and death rate are high (about 35–40 per thousand) and fluctuate; population growth is slow. Society is agrarian, illiterate, with poor medical facilities. Example: most of the world before 1750; very few areas today.
2. Stage II – Early expanding: death rate falls rapidly due to better medicine, sanitation and food supply, but birth rate remains high; population grows rapidly (population explosion). Example: many least-developed countries such as Afghanistan, parts of Africa.
3. Stage III – Late expanding: death rate continues to fall slowly and birth rate also begins to fall due to urbanisation, education, family planning; population still grows but more slowly. Example: India, Brazil.
4. Stage IV – Low stationary: both birth and death rates are low; population is stable with very low growth. Example: USA, Australia, western Europe.
5. Stage V – Declining: birth rate falls below death rate; population decreases and ageing increases. Example: Japan, Germany, some east European countries.

Diagram (described in words): draw time on the X-axis and birth/death rate on the Y-axis; show the birth-rate line and the death-rate line both high in Stage I, the death-rate line falling sharply in Stage II while birth rate stays high, the birth-rate line falling in Stage III, both low in Stage IV and the birth-rate line below the death-rate line in Stage V; shade the gap between the lines as natural increase and draw the total population curve rising steeply in Stages II–III and levelling off.

Significance: the theory helps understand the population situation of a country and plan for it; its limitation is that it is based on the European experience and may not apply exactly to every country.