The changes in population growth rates and the effect on
population can be shown on the Demographic Transition Model
(Population Cycle) - see diagram below:
This can be divided into four stages:
Stage 1 - High Fluctuating
Birth Rate and Death rate are both high. Population growth is
slow and fluctuating.
Reasons
Birth Rate is high as a result of:
Lack of family planning
High Infant Mortality Rate: putting babies in the 'bank'
Need for workers in agriculture
Religious beliefs
Children as economic assets
Death Rate is high because of:
High levels of disease
Famine
Lack of clean water and sanitation
Lack of health care
War
Competition for food from predators such as rats
Lack of education
Typical of Britain in the 18th century and the Least
Economically Developed Countries (LEDC's) today.
Stage 2 - Early Expanding
Birth Rate remains high. Death Rate is falling. Population
begins to rise steadily.
Reasons
Death Rate is falling as a result of:
Improved health care (e.g. Smallpox Vaccine)
Improved Hygiene (Water for drinking boiled)
Improved sanitation
Improved food production and storage
Improved transport for food
Decreased Infant Mortality Rates
Typical of Britain in 19th century; Bangladesh; Nigeria
Stage 3 - Late Expanding
Birth Rate starts to fall. Death Rate continues to fall.
Population rising.
Reasons:
Family planning available
Lower Infant Mortality Rate
Increased mechanization reduces need for workers
Increased standard of living
Changing status of women
Typical of Britain in late 19th and early 20th century; China;
Brazil
Stage 4 - Low Fluctuating
Birth Rate and Death Rate both low. Population steady.
Typical of USA; Sweden; Japan; Britain
Applied Revision Table
Area
Birth Rate
Reason
Death Rate
Reason
LEDCs
High
No contraception
Couples have many babies to compensate for the high death rate caused by poor
health care
Large families need to work on the land to contribute to family income
Children look after old
Religious reasons
High
Poor medical facilities
Disease
Poor nutrition
High Infant mortality
NICs
High/
Decreasing
People are used to having many children. Takes time for culture to change
Changing status of women
Decreasing
As an economy develops money becomes available for better health care
Housing improves
Better childcare
MEDCs
Low
Children are expensive
People know their children are going to survive so they can keep their families
small
Widely available contraceptives
Changing status of women
Low
Better health care
Better standard of living
Is the model universally applicable?
Like all models, the demographic transition model has its
limitations. It failed to consider, or to predict, several factors and events:
1 Birth rates in several MEDCs have fallen below death rates
(Germany, Sweden). This has caused, for the first time, a population decline
which suggests that perhaps the model should have a fifth stage added to it.
2 The model assumes that in time all countries pass through the
same four stages. It now seems unlikely, however, that many LEDCs, especially in
Africa, will ever become industrialised.
3 The model assumes that the fall in the death rate in Stage 2
was the consequence of industrialisation. Initially, the death rate in many
British cities rose, due to the insanitary conditions which resulted from rapid
urban growth, and it only began to fall after advances were made in medicine.
The delayed fall in the death rate in many developing countries has been due
mainly to their inability to afford medical facilities. In many countries, the
fall in the birth rate in Stage 3 has been less rapid than the model
suggests due to religious and/or political opposition to birth control (Brazil),
whereas the fall was much more rapid, and came earlier, in China
following the government-introduced ‘onechild’ policy.
The timescale of the model, especially in several South-east
Asian countries such as Hong Kong and Malaysia, is being squashed as they
develop at a much faster rate than did the early industrialised countries.
4 Countries that grew as a consequence of emigration from
Europe (USA, Canada, Australia) did not pass through the early stages of the
model.
