Model of Population Cycle

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 
• 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