Topic: Population Pyramids

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

• 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 country’s 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

Age/Sex Distributi

on:• 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 = 95:100

– Rest of World = 102:100

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

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 = Dependents15-64 = Workers64+ = Dependents

Population Pyramids:

• A country’s 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 country’s population pyramid tell a lot about the country

• 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.

For wealthier countries, the chart is shaped like a lopsided vase. Population is aging, TFRs

are declining.

For poorer countries, the chart is shaped like a pyramid. Infant mortality rates are high, life

expectancy is shorter.

• Four Patterns of Population Structure• Each nation faces different problems due to a large

base with many young or negative growth.

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.

Population ofGermany, 1989Germany’s 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.

• Attendants or “pushers” on the Japan Train system. Despite having a declining population, Japan has a very high population density.

JAPAN’S CHANGING POPULATION PYRAMIDS Japan’s 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.

Slow Growth:• A country in stage 4 of the Demographic Transition Model

• Large number of “older people”• Smaller % of young people

No Growth:• End of stage 4, entering Stage 5• Large number of “older people”• Very small % of young people

Affect of AIDS on population pyramid for

South Africa.

Predicted population for 2035, without and with AIDS.

With AIDS, looks like a population “chimney.”

AIDS is leaving large numbers of AIDS orphans.

• 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 Africa’s 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.

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

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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