Page 575 - Sociology and You

Chapter 16 Population and Urbanization
545
Developed Nations Less Developed Nations
85+
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
300 200 100 0 100 200 300
Population in millions
Males
Females
85+
80–84
75–79
70–74
65–69
60–64
55–59
50–54
45–49
40–44
35–39
30–34
25–29
20–24
15–19
10–14
5–9
0–4
300 200 100 0 100 200 300
Population in millions
Males
Females
Population Pyramids
Population pyramids
allow you to see at a glance
the age and sex composition
of a population. Age and sex
are key indexes to fertility and
mortality rates, which in turn
are used to project school and
housing needs, health re-
sources, and other key social
services. Population pyramids
illustrate the dependency ratio
that results from different rates
of population growth. The
dependency ratio is the ratio
of persons in the dependent
ages (under fifteen and over
sixty-four) to those in the
“economically active” ages (fif-
teen to sixty-four). The two as-
pects of the dependency ratio
are youth dependency and
old-age dependency. Developing nations have much higher youth dependency than developed nations. Developed nations have significantly higher old-age dependency. Figure 16.7 displays typical age-sex pyramids for developed and developing nations.
Why is the dependency ratio important? For developing countries such as Mexico, a high youth dependency means that national income must be diverted from economic development to provide food, housing, and education for its large
young population. In de-
veloped countries such
as the United States,
rising old-age depen-
dency creates a
different set of
problems.
With a larger
population pyramid
a graphic representative of the age and sex composition of a population
dependency ratio
the ratio of dependent persons to economically active persons
Figure 16.7 Age-Sex Pyramids in Developed and Less Developed Countries.
This figure shows general population patterns by age and sex in developed and developing countries. Using the dependency ratio, explain why children in developed countries are economically better off than those in the developing nations.
Source: United Nations Population Division.
America’s aging population is raising the dependency ratio. Why should that concern you?
Age in years