Pyramids of population

Population pyramids are graphic representation of population and are used to:

• Population distribution
• Population change, for upper levels (because the majority of lower level
• Identify ratios male:female

Stage 1: EXPANDING

High CBR, rapid fall in each upward age group due to high CDR, short life expectancy

Stage 2: EXPANDING

High CBR, fall in CDR as more individuals live to middle age, slightly longer life expectancy

Stage 3: STATIONARY

Declining CBR, low CDR, more individuals live to old age.

Stage 4:CONTRACTING

Low CBR, low CDR, higher dependency ratio (those that cannot work), longer life expectancy

*LEDCs tend to be stage 1 or 2

*MEDCs tend to be stage 3 or 4