1. Age Structure and Population Limits

2. Questions for Today:
What are the different age structures of a population and how will they determine future growth?
What are different ways to slow down population growth?
What are the four different stages in human population growth?
What is the number one method to curb population growth?

3. Age Structures
Age structure is the distribution of males and females among age groups in a population.
Analyst plot the percentages of numbers of males and females in age structure diagrams or pyramids
Three types of age structures:
Prereproductive (0-14)
Reproductive (15-44)
Postreproductive (45 and older)
Nearly 28% of the people on the planet were under 15 years of age in 2008

4. Age structure Diagrams
Male
Female
Expanding Rapidly Guatemala
Nigeria
Saudi Arabia
Expanding Slowly United States Australia
China
Stable
Japan
Italy
Greece
Declining
Germany
Bulgaria
Russia
Prereproductive ages
0–14
Reproductive ages
15–44
Postreproductive ages
45–85+

5. Age Structures
Age structure vary in developed countries and developing countries.
Developing countries will have a higher percentage of people in the prereproductive ages than developed countries.

6. Figure 6.9
Global outlook: population structure by age and sex in developing countries and developed countries, Question: If all girls under 15 had only one child during their lifetimes, how do you think these structures would change over time? (Data from United Nations Population Division and Population Reference Bureau)
Fig. 6-9a, p. 131

7. Population (millions)
Developing Countries
85+
80–85
75–79
Male
Female
70–74
65–69
60–64
55–59
50–54
45–49
40–44
Age
35–39
30–34
25–29
Figure 6.9
Global outlook: population structure by age and sex in developing countries and developed countries, Question: If all girls under 15 had only one child during their lifetimes, how do you think these structures would change over time? (Data from United Nations Population Division and Population Reference Bureau)
20–24
15–19
10–14
5–9
0–4
300
200
100
100
200
300
Population (millions)
Fig. 6-9b, p. 131

8. Age Structures What happens when your pyramid is inverted? Japan:
Population 2008: 128 million
Population 2050: 96 million
The Majority of Japan’s population is reaching their postreproductive ages.

9. Rising Death Rates
Aside from a disproportion in the age structures, one of the major causes for population decline is AIDS and HIV.
AIDS can affect a population by:
Lowering life expectancy
Loss of workforce

10. Slowing Population Growth
Four major stages in demographic transition.
Preindustrial
Transitional
Industrial
Postindustrial
As more developing countries move into the developed category, we will see a boom in population.

11. Birth rate and death rate
Population
grows very
slowly because
of a high
birth rate
(to compensate
for high infant
mortality) and a
high death rate
Stage 1
Preindustrial
Growth rate over time 80 70 60 50 40 30 20 10
(number per 1,000 per year)
Birth rate and death rate
Low
Death rate
Total population
Birth rate
Population grows rapidly because birth rates are high and death rates drop because of improved food production and health
Decreasing
Stage 2
Transitional
Increasing
Very high
Population growth slows as both birth
and death rates drop because of improved food production, health, and education
Stage 3
Industrial
Low
Population growth levels off and then declines as birth rates equal and then fall below death rates
Stage 4
Postindustrial
Negative
Zero
Figure 6.12
Four stages of the demographic transition, which the population of a country can experience when it becomes industrialized. There is uncertainty about whether this model will apply to some of today’s developing countries. See an animation based on this figure at CengageNOW. Question: At what stage is the country where you live?
Stepped Art
Fig. 6-12, p. 134

12. Methods to slowing population growth
Family Planning
Family planning provides educational and clinical services that help couples choose how many children to have and when to have them.
Varies from culture to culture
A Major Factor in reducing the number of births throughout the world
55% of a drop in TFR because of FP.

13. Family Planning Two problems:
Most pregnancies in developing countries are unplanned and end with, usually, an illegal abortion.
The lack of access to family planning services.

14. Family Planning Examples of Government Funded Family Planning:
China’s One Child Policy
Prefer Males
Pledge to have one child, reap many benefits!
India’s Family Planning
Government provides Information and resources, but Couples still believe having large families is the best.

15. Empowering Women
Studies show that women who are educated, hold a paying job, and live in societies where their rights are not suppressed have fewer children.