Page 34 - bfw-APHG-1e

80°N 80°N
Arctic Circle
Arctic Circle
60°N 60°N

40°N 40°N
ATLANTIC
OCEAN Tropic of Cancer
Tropic of Cancer
20°N 20°N
PACIFIC PACIFIC
OCEAN OCEAN
Equator
0° Equator 0°
INDIAN
Significantly younger or OCEAN
older populations, 2017 20°S
40% or more are 15 ATLANTIC Tropic of Capricorn
Tropic of Capricorn
years of age or younger OCEAN
40°S 15% or more are 65 40°S
40°S
40°S
years of age or older 0 2000 4000 miles
Other countries 0 2000 4000 km
No data 160°W 140°W 120°W 100°W 80°W 60°W 40°W 20°W 0° 20°E 40°E 60°E 80°E 100°E 120°E 140°E 160°E 180°
120°W
140°W
160°W
Figure 8.1 The world pattern of youth and old age. How would you describe the spatial pattern of younger national populations and
older national populations?

A population’s age structure can help us predict its In other words, every 100 working-age people in this
future population growth, allowing us to estimate how country will support 50 dependents. The higher the
many young people will need education and employ- dependency ratio, the heavier the burden of support.
ment and how many elderly people we will need to sup- The value of this ratio varies considerably from one
port. These numbers also help us predict consumption country to another. Countries with a high dependency
patterns because young people and older people have ratio, such as Somalia, Guatemala, and Syria, may
very different needs. A country with a large population need to devote a considerable amount of resources to
of young people will likely spend a lot of money on edu- supporting its people, which could divert money from
cation, while a country with many elderly people will investments and economic development.
likely spend a lot of money on health care. Because the younger and older members of a
society have very different needs, we may also calcu-
Dependency Ratios late the dependency ratio separately for these two
groups. The youth dependency ratio focuses on those
One implication of a county’s age structure is the too young to work (usually people younger than
dependency ratio, or the number of dependents in a pop- 15 years old). The elderly dependency ratio focuses on
ulation that each 100 working-age people (ages 15–64)
must support. Dependents are people who are younger
than 15 years of age and people who are older than 65, TERMS TO KNOW . . .
roughly corresponding to those too young to work or dependency ratio: The number of dependents in a
retired. The dependency ratio is usually calculated by population, that each 100 working-age people (ages
dividing the number of dependents by the working-age 15 to 64 years) must support
population. So, for example, if a country has 15 million youth dependency ratio: The number of young depen-
young dependents, 5 million older dependents, and dents in a population (usually people younger than 15 years
40 million people of working age, then its dependency of age) that every 100 working-age people must support
ratio is elderly dependency ratio: The number of elderly depen-
(15 + 5) = 50 percent dents in a population (usually people older than 64 years of
40 age) that every 100 working-age people must support

Module 8 Population Composition 23
©2021 BFW Publishers. Sample material is NOT FINAL and corrections will be made prior to publication.

02_Hildebrhgap1e_19224_unit02_002_131_4pp.indd 23 05/19/20 6:03 PM