c.Class Notes #12.5

Last class' notes:

Total Fertility Rate (TFR)- average of children born per woman.

For a population to remain the same, the TFR must be 2.1.

Higher than 2.1, population rises.

Lower than 2.1, population falls.

World total fertility rate is 2.42.

The US' total fertility rate is 2.01, but due to its high migration, its population still rises.

Nigeria's total fertility rate is 6.89.

Japan's total fertility rate is 1.4.

Current class' notes:

Population pyramids

- We use population pyramids to analyze growth (or decline) of fertility, mortality, and migration in cities and countries.

- Graphed in bar graphs (males are always on the left).

There are three basic shapes to represent population:

The Christmas tree (developing nations):

- Growth rates are slow.

- High birth rate.

- Short life expectancy.

The box (developed nations; slow growth):

- Low infant mortality.

- Slow population growth.

- Long life expectancy.

The cup

- Low fertility rate.

- Shrinking population.

- Long life expectancy.