Monday, 17 October 2011

The demographic transition model

The demographic transition model shows population change over time. It studies how birth rate and death rate affect the total population of a country.
The five stages of the demographic transition model
1 - Total population is low but it is balanced due to high birth rates and high death rates.
2 - Total population rises as death rates fall due to improvements in health care and sanitation. Birth rates remain high.
3 - Total population is still rising rapidly. The gap between birth and death rates narrows due to the availability of contraception and fewer children being needed to work - due to the mechanisation of farming. The natural increase is high.
4 - Total population is high, but it is balanced by a low birth rate and a low death rate. Birth control is widely available and there is a desire for smaller families.
5 - Total population is high but going into decline due to an ageing population. There is a continued desire for smaller families, with people opting to have children later in life.

As a country passes through the demographic transition model, the total population rises. Most LEDCs are at stage 2 or 3 (with a growing population and a high natural increase). Most MEDCs are now at stage 4 of the model and some such as Germany have entered stage 5.