Topic: Population Pyramids

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Topic Population Pyramids

• Aim What can the analysis of Population Pyramids
  reveal about a country?

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• Population Structure
• Fertility and mortality vary not only spatially
  but also temporally within a country.
• A special bar graph known as a population pyramid
  can visually display a countrys distinctive
  population structure.
• X-axis
• Percent male displayed to the left of zero
• Percent female displayed to the right of zero
• Y-axis
• Age cohorts typically grouped in 5-year intervals
• Youngest displayed at bottom and oldest at top

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Age/Sex Distribution

• Sex Ratio Number of males per hundred females in
  the population
• More males are born each year, but they have
  lower life expectancy
• Varies greatly from country to country
• Examples
• Europe and North America 95100
• Rest of World 102100

Russia and other European countries have high
percentages of elderly people who need pensions,
health care, and other services.
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Age Distribution

• Dependency Ratio number of people who are either
  too old or too young to work (dependents),
  compared with those people in their productive
  years
• The higher the dependents, the greater the
  financial burden on working population

Dependency Ratio 0-14 Dependents 15-64
Workers 64 Dependents
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Population Pyramids

• A countrys stage in Demographic Transition gives
  it a distinctive population structure that
  displays age and gender of a given population
• Males are on left, females on right.
• Youngest people on base of pyramid and older
  people at the top
• The shape of a countrys population pyramid tell
  a lot about the country

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• Each 5 year group with the youngest 0-4 years old
  at the base of the pyramid are called cohorts.
• A wide-based pyramid indicates a country in Stage
  2 of the Demographic transition.

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For wealthier countries, the chart is shaped like
a lopsided vase. Population is aging, TFRs are
declining.
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For poorer countries, the chart is shaped like a
pyramid. Infant mortality rates are high, life
expectancy is shorter.
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• Four Patterns of Population Structure
• Each nation faces different problems due to a
  large base with many young or negative growth.

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POPULATION PYRAMIDS FOR THE UNITED STATES AND
SELECTED U.S. COMMUNITIES Laredo has a broad
pyramid, indicating higher percentages of young
people and fertility rates. Lawrence has a high
percentage of people in their twenties because it
is the home of the University of Kansas. Naples
has a high percentage of elderly people,
especially women, so its pyramid is upside down.
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Population of Germany, 1989
Germanys population profile is that of a wealthy
core country that has passed through the post war
baby boom and has a low birthrate. Note the
impact of the losses of World War I and World War
II.
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• Attendants or pushers on the Japan Train
  system. Despite having a declining population,
  Japan has a very high population density.

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JAPANS CHANGING POPULATION PYRAMIDS Japans
population pyramid has shifted from a broad base
in 1950 to a rectangular shape. In the future,
the bottom of the pyramid is expected to contract
and the top to expand.
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Slow Growth

• A country in stage 4 of the Demographic
  Transition Model
• Large number of older people
• Smaller of young people

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No Growth

• End of stage 4, entering Stage 5
• Large number of older people
• Very small of young people

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Affect of AIDS on population pyramid for South
Africa. Predicted population for 2035, without
and with AIDS. With AIDS, looks like a population
chimney.
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• AIDS is leaving large numbers of AIDS orphans.

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• 1995 Population Pyramids reflect the economic
  prosperity of Western Europe and the less
  developed countries of Sub-Saharan Africa. In
  the mid-1990s almost 50 of Africas population
  was under 15 years of age.
• By contrast the number of people 65 and older in
  Western Europe is 5 times that of sub-Saharan
  Africa.

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What do these pyramids reveal about their
respective nations? List all the information you
can surmise, both explicit and implicit.
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Age Structure of a Population

• The populations of many areas are aging. Europe
  and Japan are good examples, whereas some nations
  have very young populations (e.g. - Iran where
  the median age is 26.4 years for males)

Bordeaux, France
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Summary Free Response