Demographic transition is a model that explains population changes over time. It works by showing how fertility and mortality rates vary in developing societies. (Editorial Board, 2013) In 1929, American demographer Warren Thompson's interpretations started the demographic transition model. It has helped to outline the changes in fertility, mortality, as well as the birth and death rate changes in developing societies. (Editorial Board, 2013) While the model helps to generalization the population changes for groups it is not always an accurate picture for individuals.
Four Phases of Demographic Transition.
Within demographic transition there are four different phases. These phases in order are;.
1. Phase I – pre-modern (primitive stability).
2. Phase II – urbanizing/industrializing (epidemiologic transition).
3. Phase III - Mature industrial (fertility transition).
4. Phase IV – Post Industrial (modern stability).
Phase I of the demographic transition has a stable population. The birth and death rates are both high and the population grows slowly. ("Demographic transition," 2014) The mortality rate is high due to the prevalence of communicative diseases and the lack of modern medicine. This phase is the beginning phases of developing countries. There is poor hygiene with little to no clean water or sewage disposal. There is little to no family planning or contraceptives. ("Demographic transition," 2014) Families tend to have many children because few live to adulthood. .
Phase II of demographic transition is characterized by a growing population. There is a rapid drop in death rates and the birth rates remain high. Mortality rates decline due to improved medicine, sanitation, and more access to clean water supplies. ("Demographic transition," 2014) Food productions are improved and there is better access to food that is healthy as well as diverse. Child mortality is declined which in turn causes the birth rates very slowly decline.
