The three stages of demographic transition-

• The First Stage- It is marked by high fertility and high mortality. The death rate is also high due to epidemics and variable food supply. So, the population growth is slow and life expectancy is low. People are mostly illiterate and their main work is agriculture due to which large families are preferred and the use of technology is low.

• Second Stage- In this stage, the expansion of population remains high because the death rate reduces due to the improvement of medical facilities and sanitation but the fertility rate is high. At the later stage, it declines. The mortality rate also decreases.

• The Third Stage- In the last stage, both fertility and mortality decline considerably. Population in the third stage is either stable and grow slowly. The family size is controlled and mostly population becomes urbanized and literate. There is a high level of technical knowledge. High technical knowledge contributes deliberately in controlling the family size.