Chapter 5
One Billion and Counting:
The Hidden Momentum of Population Growth in India
A. Logistics
Students’ Time Requirements
Activity 1: Matching Demographic Descriptions with Population Pyramids
Activity 2: Demographic Momentum
Activity 3: Interpreting Population Change
15 minutes
50–75 minutes
45 minutes
Activities 1–3 are cumulative. Activity 1 builds familiarity with age-sex pyramids and
exposes students to the different types of age-sex distributions found in the world today. Activity
2 is a simulation showing how the shape of an age-sex pyramid changes over time under
different fertility assumptions. Students use the concept of an age-sex pyramid in Activity 1 and
the results of the simulations in Activity 2 to write an interpretive essay about the hidden
momentum of population growth built into the age-sex pyramids in Activity 3. Although we
recommend doing all three parts of this exercise, you can stop after either Activity 1 or Activity
2 if you need to shorten the activity. You cannot, however, work backwards doing only Activity
3 or only Activities 2 and 3. Students cannot write the interpretive essays of Activity 3 without
having done the simulations in Activity 2. Similarly, students won’t understand much of Activity
2 unless they have familiarized themselves with age-sex diagrams in Activity 1.
Activity 1 is structured so that students are assured of getting the correct answers. If they
cannot match the appropriate age-sex pyramid to the description provided, they are advised to try
again until they find the correct answer.
In Activity 2, they should score close to 100%. Most of the answers are straightforward.
Students are also asked to describe the shape of the pyramid in a given year or indicate what
happens to the base under certain simulation conditions. Students should rely on descriptions of
shapes provided in the background section (e.g., beehive-shaped), but don’t be surprised when
you get some very creative answers here, such as (real student answers): “light bulb, radish, hot
air balloon, top half of an hourglass, ice cream cone, upside-down pear, spade, tornado, turnip,
toy top, heart, four-leaf clover, kite, vase, or dumbbell.”
In Activity 3, students are asked to write an essay explaining how it is possible for a
population to continue growing for several generations after women begin averaging only two
children each. Students may have trouble understanding demographic momentum or hidden
momentum and may see it as a paradox. The simulation in Activity 2, in fact, was designed to
help students understand this phenomenon, particularly the Instant Replacement Scenario 2. So
this activity is designed to get students to synthesize what they’ve learned into a coherent
explanation of this paradox.
Activities 1–2 require access to the Internet. They can be accomplished individually or in
groups, in class, a computer laboratory or at home.
Chapter 5’s animations require little technical expertise. Everything is automated;
students have only to point and click. Conceptually, however, this exercise is one of the most
difficult to fully understand because students need to master both complicated demographic
terminology (age-specific birth rates, total fertility rate, replacement fertility, etc.) as well as a
complicated demographic principle—that growth depends both on the current relationship
between births and deaths and on the sizes of the populations at risk of giving birth and dying.
These sizes are revealed in the age-sex pyramid. In Activity 2, students also have to have basic
competence in calculating percentage change to answer some of the questions.
B. Lesson Plan
I.
Earth’s population history
1. year intervals taken to add increments of 1 billion people
2. growing percentage of global population in Asia and Africa
II.
The size, composition, and growth of populations affect the economic and environmental
well-being of nations
1. Issues related to rapid population growth and also to population decline
III.
Dynamics of population: P2 = P1 + B – D + I – O
1. Four demographic forces: (1) births, (2) deaths, (3) immigration (people moving to a
country), and (4) emigration (people leaving a country)
2. The formula shows that births (B) and in-migration (I) add to the base population
(P1), while deaths (D) and out-migration (O) subtract from it.
IV.
Measures of population change
1. Crude birth rate (CBR) – number of births per 1,000 people
2. Crude death rate (CDR) – number of deaths per 1,000 people
3. Crude rate of natural increase – growth per 1,000 people
4. Why are these rates crude? They do not account for the age structure of the
population.
V.
Demographic transition model—a model of population change
1. Concept of equilibrium—Stages 1 and 4 are equilibrium conditions
2. History of world’s population growth (Figure 5.4)—After millions of years of
extremely slow growth, the world’s population is now growing exponentially.
3. Stage 1: high birth and high death rates
4. Stage 2: high birth and declining death rates
5. Stage 3: declining birth and low death rates
6. Stage 4: low birth and low death rates
7. Countries that don’t fit the model: negative growth
8. Applicability of the demographic transition to third world populations
a.
Different economic situations
b.
No migration escape hatch for LDCs
c.
LDC populations are larger, denser, faster-growing
d.
Hidden momentum of young age-sex pyramids
VI.
Population pyramids
1.
Explanation of
a.
Two-sided bar chart for males and females
b.
Horizontal axis shows cohort size
c.
Vertical axis shows age
2.
Typical shapes
a.
Population declining
b.
Population stable
c.
Population growing slowly
d.
Population growing rapidly
3.
Relationship between age-bearing cohorts and new birth cohort
VII.
Measures of fertility
1.
Age-specific birth rate
2.
Total fertility rate (When the total fertility rate is slightly above 2.0, a population
experiences replacement fertility.)
3.
Zero Population Growth (ZPG): crude birth rate – crude death rate = 0
VIII.
Demographic momentum—tendency for a population to continue to grow long after
replacement fertility has been achieved
1.
Occurs in an age structure with a large base and small top
2.
Very few elderly at the top of pyramid are available to die
3.
Many children who will soon be in peak reproductive ages
4.
Compare the large number of children being born to the small number of elderly
dying
5.
The focus of this chapter
IX.
India
1. Reached population of 1 billion in 2000
2. Slow growth before WWII
3. Modernization in post-WWII, increasing life expectancies, lower infant mortality
rates
4. Lagging drops in fertility, still in Stage 3 of the Demographic Transition
5. Impediments to further fertility decline: low status of women, preference for boys
over girls
6. Family planning programs
a.
Forms of contraception in India
b.
Large TFR variations within India
7. Indian emigrants—diaspora over the world
a.
Commonwealth country laborers
b.
Remittances and development
c.
Destinations today: United States, Great Britain, Canada, and Australia
8.
Implications of population growth in India
a.
Supplies of freshwater are stretched to the limit
b.
Soil exhaustion and erosion
c.
Cultivating low-lying, hurricane-prone islands
d.
e.
f.
g.
h.
Overgrazing
Protein consumption is 20 percent below nutritional needs
Unable to provide social services and education
Makeshift housing in squatter settlements
Yet, remarkable economic growth, large middle class, and leadership in
the information economy
X.
Do Activities 1 and 2 in computer lab, if available. Otherwise, assign Activities 1 and 2
as homework. Prepare your students by having them guess a few pyramids in class, and then
speculate on what would happen to the population pyramid over time if replacement level
fertility were achieved overnight.
XI.
Discussion
C. Answer Key
Activity 1: Matching Demographic Descriptions with Population Pyramids
1.1
Description 1: Country C – Tanzania
Description 2: Country D – Russia
Description 3: Country E – Norway
Description 4: Country A – China
Description 5: Country F – Qatar
Description 6: Country B – Italy
Activity 2: Demographic Momentum
Scenario 1: Base Case, No Change in Total Fertility Rate
2.1
by 2065
2.2
2412.29 million / 6892 million = .35 or 35%
2.3
1189 x 2 = 2378 million. That figure is reached between 2095 (2355 million) and 2100
(2412 million).
2.4
By 2100, the pyramid is still triangular but has become less triangular and more
columnar. Each new cohort is only slightly larger than the previous (older) cohort. The
triangle is fairly narrow at the base.
2.5
No
2.6
(17.62–12.85) / 10 = 4.77/10 = 0.477%
Scenario 2: Instant Replacement Level
2.7
In about 2070. 2070 is the peak, or the year population stops going up. Prior to 2070 it is
starting to level off but it doesn’t quite level off until 2070.
2.8
1723.62 million is the peak when population stops growing.
2.9
They become more or less equal (an equilibrium is achieved). There will be small
fluctuations each year where either CDR or CBR is higher, but they are close to
equilibrium.
2.9
Just by looking at the shape of the pyramid (now with vertical sides), students should say
“yes,” the children’s generation 0–19 years old approximately replaces the parents’
generation 20–39 years old. If the student is industrious, he or she will actually total up
the values for those two age groups. For the 0–19 ages, the total population is 483
million, for the 20–39 ages, the total population is 467 million. The difference of 16
million is within the margin of error of +/– 25 million, so the answer is confirmed to be
“yes.”
There is a typo in Instruction H preceding the next question in the first printing of the 6e. In
subsequent printings, this should be fixed. On the last line of H, the date 2025 should be 2030.
2.11
Many more births—the bottom four cohorts in 2030 are much larger than the top four
cohorts in 2010. In 2010, the 65–84-year-olds who will die (in the model) by 2030 add up
to around 59 million, compared with the 483 million children born between 2010 and
2030.
2.12
It most resembles the slow-growth pyramid in Figure 5.6 (most like the U.S. or Canada in
2000), but actually it’s a nearly perfect example of a stable pyramid. However, no stable
pyramids are shown in the real-world examples of Figure 5.6.
2.13
Assuming that keeping India’s population at a lower level is the goal, then the answer is
“optimistic,” in the sense that it is optimistic to assume that fertility rates can drop by
such a large margin instantly. The transition from 2.6 to 2.3 is likely to take a decade or
more. Fertility rates reveal choices that people make about family size. These choices are
a function of cultural preferences and economic status, which can never change
overnight. Lowering fertility rates is a process influenced by a whole host of societal
factors. The bottom line is that fertility rates will not drop until people want to have fewer
children, and the change from traditional societies where many children were an asset to
more modern societies where large families are no longer necessary is a gradual one.
Scenario 3: Forty Years Until Replacement Fertility
2.14
The new peak given this 40-year delay would be 1927.86 million, which is 204.24
million people more than in the previous scenario peak.
2.15
1927.86 million (1.92786 billion)
Scenario 4: Seventy-Five Years of Delay Until Replacement Fertility
2.16
No
2.17
2073.52 million
Scenario 5: High Fertility
2.18
With TFR set at 7.0 and the delay set at 10 years, the 2100 population would be 48660.82
million (48.6 billion!)
2.19
Between 2055 (5815.96 million) and 2060 (7240.47 million)
2.20
It gets very wide at the base.
Scenario 6: Low Fertility
2.21
By 2045 (between 2040 and 2045)
2.22
It begins to decline by 2045.
2.23
It peaks at 1435.31 million
2.24
1435.31– 703.39 = 731.92 million
2.25
(7.01 – 22.22)/10 = –1.521%
Scenario 7: One-Child Policy
2.26
By 2025
2.27
1220.87 million
2.28
1220.87 – 255.19 = 965.68 million
2.29
Inverted pyramid, or perhaps a tornado!
2.30
Simply because there is a high percentage of elderly people, and age-specific death rates
are highest among the elderly. When the elderly far outnumber the young, and elderly are
dying at the rates typical of 50–80-year-olds, the crude death rate per 1000 people (of all
ages) will be very high.
Activity 3: Interpreting Population Change
3.1
Population growth is the difference between the number of births and the number of
deaths in a population. Growth is determined both by the rate at which births and deaths occur
and by the sizes of the population at risk of giving birth or dying. Most developing countries
have age-sex pyramids with steeply concave sides, large bases, and small tops. What this means
is that there are huge numbers of women about to enter their reproductive years. There are,
however, very small numbers of persons (both male and female) at the top of the pyramid where
the risk of death is high. As a result, there will be many more births than deaths in the
population, even if the number of births per woman is low. In China, for example, the total
fertility rate is 1.5 (below replacement levels) and yet the population continues to grow.
Consider also the case of India. The “instant replacement level” scenario demonstrates
what happens if India were to achieve replacement fertility (the total fertility rate = 2.3)
instantaneously. A total fertility rate of 2.3 means that the average Indian women has on average
2.3 children, and she and her husband/partner are having just enough children to replace
themselves in the next generation. Even at replacement fertility, the population growth of India
would continue until the year 2070, and the population would grow to over 1488 million. It takes
many years for the large population base of today to work itself upward into older age groups
where deaths typically occur. Only then will deaths equal births and the population achieve ZPG
or zero population growth.
D. Discussion or Essay Questions
How will the demographic transition model have to be adjusted if genetic engineering leads to
life expectancies over 100 years?
What might be the social, cultural, political, and economic implications if European fertility rates
remain near 1.0 for a long time?
What leads to fertility decline? (The overwhelming trend is for fertility to decline over time. We
know this from comparing current with past family sizes, by comparing the low fertility in moredeveloped countries with the high fertility in less-developed countries, and by comparing social
and economic groups within countries. It is almost always the most educated, well-off class that
has the lowest fertility. Fertility decline worldwide has been linked to declining rates of infant
mortality; economic shifts away from agricultural to more urban-based activities; rising levels of
education, particularly for women; increased participation of women in the work force; and the
widespread availability and adoption of contraception.)
What is meant by the expression, “development is the best contraceptive”?
If LDCs cannot achieve industrialization, are they doomed to continuing high fertility? How can
highly agricultural countries achieve low fertility?
What do you think is the ideal age for you to have children, and why?
How many people do you think the Earth can sustainably support?
Is the world overpopulated?
Is the United States overpopulated?
Is Canada underpopulated?
What might be the signals to us, as a society, that our country (or the world) is overpopulated?
Are we likely to recognize those signals and respond to them in a timely manner?
Do you agree with some economic development advocates who argue that putting artificial
contraceptives into the hands of third world women is only a Band-Aid solution to the problem
of third world development?
How do fertility levels in the U.S. compare to those in earlier times?
Using your family tree, compare fertility levels of today with those of your ancestors. What does
this family history tell us about fertility trends over the past 25 to 30 years?
Bring this exercise closer to home and have the students work through the current population
growth situation in modern Mexico and relate it to the pressure for immigration from the south.
For example, Mexico’s mid-2012 population is about 116 million. A crude birth rate of 20 (or 20
per 1,000 population) yields 2.32 million births per year. The crude death rate of 5 (or 5 per
1,000 population) yields only 580,000 deaths. This translates into growth of about 1.74 million
persons per year. How likely is it that the United States will relieve Mexico’s population growth
and absorb over 1.7 million new immigrants from Mexico per year? (Not likely, as evidenced by
the fact that we currently admit only about 1 million immigrants each year from all over the
world.)
Why should we care if the world’s population is growing rapidly? (Lead the students through a
discussion of the interconnectedness of the world’s population, economy, and environment.
Increased population in the developing world brings pressure for more immigration to North
America; it may or may not lead to increased demand for U.S. products, depending upon income
levels of the people involved; and more people exacerbate problems of air and water quality,
global warming, and pollution.)
China in mid-2012 has around 1.35 billion people, more than four times as many as the United
States. Does this justify their One-Child Family Policy, which imposes economic penalties and
revokes economic privileges for having more than one child? Would a One-Child Family Policy
like China’s work in the United States or in Europe? India? Canada?
What would the age-sex pyramid look like for:
 a summer camp (complete with staff)?
 a retirement community?
 a college town?
 the U.S. in 30 years?
 an 1849 Gold Rush mining town in California?
 the booming North Dakota oil fields today?
Should the United States government give funds to international agencies that make available
abortion or contraception or sterilization in LDCs?
Republican and Democratic politicians tend to disagree on U.S. funding for family planning in
the U.S. and around the world. Republicans tend to favor providing funds to faith-based
organizations that promote abstinence-only family planning, while Democrats tend to favor
programs that empower women to plan their family size as they best see fit, which may include
abortion. Do you think our government should pursue either of these policies, either for
Americans or for foreign aid?
Suppose algae is growing in a lake and doubling in size every day. Biologists calculate that at the
current rate, it will take over the entire lake in 30 days. On what day will it cover half the lake?
(The 29th day!) What is the relevance of this tale to modern society?
What are the domestic or international implications for a country with a large diaspora of its
people residing in other countries?
Do you feel immigrants to the United States are a net gain or net loss for the U.S. economy?
How about in terms of social and cultural change in the country?
E. Question Bank
1. True/False Anything that grows as a constant percentage of its own size will double in a
given number of years, and then will double again in the same number of years,
assuming the growth rate stays exactly the same.
2. True/False Most third world countries today are in Stage 1 of the demographic transition.
3. True/False A majority of the world’s population resides in developed countries.
4. True/False In the third stage of the demographic transition, death rates level off at a low
level, and birth rates fall dramatically.
5. True/False Immigration counts for most of the population growth in most countries.
6. True/False The crude death rate declines earlier than the crude birth rate as countries pass
through the demographic transition.
7. True/False Countries never reach equilibrium in population growth.
8. True/False The demographic transition model applies equally well to developed and
developing countries.
9. True/False Since the 1970s, the total fertility rate in India has declined.
10. True/False Women in India enjoy near-equal status as males
11. True/False The concern in some countries over the future solvency of government
funded retirement plans can be directly related to the demographic outcome of a
low fertility rate.
12. True/False The demographic transition model describes a transition from a fairly stable
population with high crude birth and death rates to a fairly stable population with
low crude birth and death rates.
13. True/False Persistent poverty is partly the result of a rapid growth rate in some countries of
the world today.
14. True/False The ideal total fertility rate (TFR) for many countries is 3.
15. Demographic momentum is the phenomenon that:
a.
life expectancies take more than a generation to slow down
*
b.
population growth continues for about a generation after replacement fertility is
reached
c.
requires that TFR must fall from replacement level to exactly 2.0
d.
developing countries take very little time to complete the demographic transition
e.
developing countries cannot freeze the demographic transition and remain in
Stage 3, no matter how hard they try
f.
democratic societies resist the imposition of a one-child policy
16. Demographic momentum is due to:
*
a.
a youthful age distribution in the population pyramid
b.
an elderly age distribution in the population pyramid
b.
unbalanced sex ratios that strongly favor males over females
c.
rapidly changing life expectancies
d.
increasing birth rates
17. The total fertility rate is:
a.
the number of births per 1000 people
b.
the number of female births per 1000 people
c.
the number of births per 1000 females
d.
the difference between the crude birth rates and the crude death rate
*
e.
the average number of children that a female has as she passes through her
reproductive years
18. An age-sex diagram shaped like a diamond would describe which of the following
populations?
a.
a rapidly growing population
b.
a slow-growing population
c.
a stable population
*
d.
a declining population
19. Why is Germany’s crude death rate higher than India’s?
a.
declining quality of life in Germany
b.
widespread out-migration in Germany
*
c.
Germany’s older population
d.
erroneous death statistics
20. In what stage of the demographic transition does India today best fit?
a.
Stage 1 (high birth and death rates)
b.
Stage 2 (high birth and declining death rates)
*
c.
Stage 3 (declining birth rates and low death rates)
d.
Stage 4 (low birth and death rates)
21. Which is not a difference between the less-developed countries and the more-developed
countries as they pass through their demographic transitions?
a.
the LDC economies are profoundly different than the MDC populations upon
which the model was based
b.
the LDC are more heavily populated than were the MDCs when they went
through the demographic transition
c.
the LDCs have fewer out-migration safety-valve destinations
d.
the death rate decline is occurring much more rapidly in the LDCs than it did in
the MDCs
*
e.
the demographic transition in the LDCs is taking much longer than in the MDCs
22. The age-specific fertility rate indicates
*
a.
the number of births per woman in a certain age cohort
b.
the average number of children per family in a country
c.
the average age of women giving birth
d.
the rate of fertile women in each age cohort
e.
the ratio of female to male births
23. India’s population just passed what level in the year 2000?
a.
500 million
*
b.
1 billion
c.
2 billion
d.
100 million
e.
none of the above
24. Rumors of what population policy contributed to the ouster of President Indhira Gandhi in
the 1970s?
a.
infanticide of baby girls
b.
lack of any family planning program
c.
promotion of large families and no use of contraception
*
d.
forced sterilization
e.
distribution of faulty birth control pills
25. When a country has scattered settlements of their national group living abroad, this is a:
a.
hegemony
*
b.
diaspora
c.
population pyramid
d.
demographic transition
e.
hidden momentum
26. Which of the following demographic trends are caused by later marriage age, women
moving into the workforce and higher education, introduction of social security plans for old age,
a shrinking percentage of people engaged in agriculture, and people moving into cities?
a.
decline of CBR in Stage 2 of the demographic transition
*
b.
decline of CBR in Stage 3 of the demographic transition
c.
decline of CDR in Stage 2 of the demographic transition
d.
decline of CDR in Stage 3 the demographic transition
27. The world’s population is currently around
a.
800 million (800,000,000)
b.
200 billion (200,000,000,000)
*
c.
6.5 billion
d.
22 billion
e.
2.7 million
28. According to the following age-sex diagram, Japan’s population pyramid signifies that
Japan’s population is most likely
*
a.
declining
b.
increasing
c.
currently in the midst of a “baby boom”
29. A country with a CBR of 45 per 1000 and a CDR of 12 per 1000 has a natural increase rate
of
a.
5.7%
b.
57%
*
c.
3.3%
d.
e.
33%
undetermined because the net migration rate is not given
30. What is the term defined by the following phrase? "Annual number of live births per 1,000
population."
*
a) crude birth rate
b) crude rate of natural increase
c) crude death rate
d) age-specific birth rate
e) replacement fertility birth rate
31. What is the term defined by the following phrase. "Annual number of deaths per 1,000
population?"
a) crude birth rate
b) crude rate of natural increase
*
c) crude death rate
d) age-specific death rate
e) replacement death rate
32. What is the term defined by the following phrase. "Number of deaths of children under 1
year of age per 1,000 live births in a year?"
a) crude birth rate
b) crude death rate
c) rate of natural decrease
d) rate of infant deaths by natural causes
*
e) infant mortality rate
33. This population pyramid for Algeria is just into which stage in the demographic transition?
*
a) Stage 1
b) Stage 2
c) Stage 3
d) Stage 4
34. This population pyramid for the Sudan is squarely in which stage in the demographic
transition?
*
a) Stage 1
b) Stage 2
c) Stage 3
d) Stage 4
35. Which stage of the demographic transition model has both high birth and high death rates,
resulting in a fairly stable total population?
*
a) Stage 1
b) Stage 2
c) Stage 3
d) Stage 4
36. Which stage of the demographic transition model has both low birth and low death rates,
resulting in a fairly stable total population?
a) Stage 1
b) Stage 2
c) Stage 3
*
d) Stage 4
37. Which two stages of the demographic transition Model does the most population growth
occur in?
a) Stages 1 and 2
*
b) Stages 2 and 3
c) Stages 3 and 4
38. In which of the two stages in the demographic transition Model is there population
equilibrium?
a) Stages 1 and 2
b) Stages 2 and 3
c) Stages 3 and 4
*
d) Stages 1 and 4
39. Replacement fertility compares what two groups to each other? (You must choose both
correct answers and nothing else in order to get credit for this question.)
*
a) births
b) teenagers
*
c) parents
d) elderly generation (i.e. the oldest age cohorts)
40. Zero population growth compares which two groups to each other? (You must choose both
correct answers and nothing else in order to get credit for this question.)
*
a) births
b) teenagers
c) parents
*
d) elderly generation (i.e. the oldest age cohorts)
41. Which of the following has not been a factor in reducing the population growth rate in India
in recent years? (Choose the best answer.)
a) an increase in the average marrying age
b) increased education for women
*
c) an inability to decrease their relatively high rates of infant mortality
d) economic development
e) sterilization incentive programs
42. In what stage of the demographic transition does the U.S. today best fit?
a) Stage 1
b) Stage 2
c) Stage 3
*
d) Stage 4
43. According to its population pyramid above, Germany’s population is most likely:
*
a) declining
b) increasing
c) currently in the midst of a “baby boom”
44. From the pyramids above, which country’s population will increase at the greatest rate, or
has the most momentum?
a) Germany
b) New Zealand
*
c) Egypt
45. From its population structure, Egypt is probably in which stage of the demographic
transition?
a) Stage 1
*
b) Stage 2
c) Stage 4
d) Stage 5
46. Countries such as Russia and the Ukraine have negative rates of natural increase and lose
about 1% of their population annually. According to the textbook, this can be attributed to:
a) a yet-to-be-theorized fifth stage in the demographic transition model where births fall below deaths.
* b) a temporary anomaly resulting from the historical, geographical, political, and economic context of
those countries.
c) UFOs
d) the inherent inaccuracy of the demographic transition model.
47. Which of the following associations regarding the demographic transition model is
INCORRECT?
a) Stage 1 : pre-modern equilibrium
*
b) Stage 2 : high growth, but declining population growth
c) Stage 3 : early modernization
d) Stage 4 : highly developed countries, for example the U.S. and Canada
48. In the demographic transition model, why does the drop in the crude birth rate lag so far
behind the earlier drop in the crude death rate?
a) The drop in the crude death rate is largely a cultural change, and therefore tends to happen
rapidly while the drop in the crude birth rate is more technological and tends to take much
longer.
b) While both changes happen due to technological shifts, the crude birth rate lags due to a
generational gap.
*c) The drop in the crude death rate is largely a technological change, and therefore tends to
happen rapidly while the drop in the crude birth rate is more cultural and tends to take much
longer
d) This is just the natural course of events moving from pre-modern to postmodern times
49. In what stage of the demographic transition do countries such as the U.S. and Canada best
fit?
a) Stage 1
b) Stage 2
c) Stage 3
*
d) Stage 4
50) Zero population growth (ZPG) is finally reached when ______________.
a) the crude birth rate and crude death rate both fall to 0.
b) the crude birth rate falls to 0.
* c) the crude birth and death rates reach the same level.
d) the total fertility rate reaches 2.0.
e) the total fertility rate reaches 2.3.
51) What is the difference between population change and natural increase?
* a) Population change includes births, deaths, and migration, while natural increase includes
only births and deaths.
b) Natural increase includes births, deaths, and migration while population change includes
only births and deaths.
c) Population change and natural increase are synonymous; they measure the same thing.
d) It depends: in some situations natural increase includes migration, but in others it does not.
52. Which of the following is NOT a factor in total population change
a) Crude birth rate
b) Crude death rate
c) In-migrants
*
d) All of the above are factors
e) A and B are not factors
53. Question: Based on what you learned in Chapter 5, explain what is meant by the "momentum
of population growth"? Why is it "hidden"?
Answer: Even if birth rates fall dramatically will continue to grow until population ages and
crude death rate becomes equivalent to crude birth rate, it is "hidden" because it seems like it
would not happen
54. In your own words, explain the difference between a country reaching “Replacement
Fertility” and “Zero Population Growth.”
Answer
Textbook definitions: Replacement Fertility: The fertility rate at which each female in a
population produces on average one female baby who survives to the time when she herself can
reproduce. Zero Population Growth (ZPG): A state in which the crude birth rate minus the crude
death rate equals zero. The number of deaths exactly offsets the number of births.
55. Based on what you know about demography, explain how it is possible for a country’s
population to continue growing for several generations after women begin averaging only two
children each (i.e., replacement fertility). How does it come to pass much later that the
population eventually does stabilize?
Answer
Even if a generation only just replaces itself, the population of a country will continue to grow
because the number of people in the child-producing age groups continues to grow for at least a
generation (the base of children is wider than the current generation of people having children).
Not until much later, when the death rate starts to equal the birth rate, will the total population
stabilize. In large part this does not happen right away because the narrow top of a population
pyramid at the beginning stages of replacement fertility reflects a small percentage of elderly,
and therefore a low death rate, since these are the age categories in which most deaths occur.
F. Related Issues
Frequently asked questions (of the simulation model):
How does the computer calculate the annual fertility rate in cases where the fertility rate
is changing over time?
It linearly interpolates between 2.6 in 2010 and some other fertility rate X years
later. For instance, if the TFR is set to 2.0 in 15 years, the TFR would be 2.6 in
2010, 2.4 in 2015, 2.2 in 2020, and 2.0 in 2025.
How is the TFR used to predict the number of births?
The model contains data on the age-specific fertility shares for females of
different ages. For instance, 15–19-year-olds have 7.4% of all births, and 20–24year-olds have 39.6%. So, if the TFR is 3.0, then the number of births to women
ages 20–24 is 39.6% of 3.0 children times five years.
These percentages, which can be seen in the worksheet, add up to 100% between
ages 10 and 50. The percentages used in the model are the actual age-group shares
in India in 2011. As such, they reflect a somewhat earlier birth pattern of a typical
middle-income country rather than the later birth pattern of a typical developed
country. A more sophisticated model would adjust these shares in accordance
with the TFR at the time.
Which total number of 20–24-year-old females is used in the above calculation: the
number who were 20–24 in the starting pyramid, or the number who move up into the
20–24-year-old bracket five years later?
In predicting births from year t to year t + 1, we use the number of women in year
t. This is mostly an arbitrary decision, since there is some error either way you do
it. For instance, a 15-year-old in 2000 would remain in the 15–19 bracket for most
of the entire five years, so the assumption to apply the 15–19 fertility share to her
is reasonable. On the other hand, a 19-year-old in 2000 will spend most of the
next five years in the 20–24-year-old bracket, and should rightfully have a higher
fertility.
How are deaths handled by the simulation model?
We input the survival rates for males and females for each age bracket. For
instance, 93.3% of newborn females in India in 2010 were likely to survive until
age 5. So, the model takes the number of females in the 0–4-year-old age bracket,
multiplies it by .933, and puts that number in the 5–9 bracket in 2005. The
survival rates can be seen in the worksheet.
In Scenario 1, why does the CBR spike up in 2015? One wouldn’t expect such a dramatic
change given that the TFR is unchanged at 2.6.
We call this the “business-as-usual” scenario, but it isn’t really. The TFR may
have been 2.6 in 2010, but it had been gradually dropping over the previous 25
years. More than anything, business-as-usual was a condition of a steadily falling
TFR. So freezing it at 2.6 isn’t exactly “business as usual.” Notice that in 2010,
the sizes of the 0–4 and 5–9 cohorts are almost identical. Although the TFR had
been steadily declining, this had been offset by a greater number of women in
their reproducing ages. The net result was a constant number of births. Now, in
our Scenario 1, we suddenly freeze the TFR at 2.6, but we continue to move more
women into the reproducing ages, so the number of births jumps. It makes
demographic sense, given our assumptions.
Also, there are some discrepancies in the cohorts over time in the Census India
data. We use historical data for each cohort for 2000, 2005, and 2010. In 2000, the
number of males ages 0–4 was 59.9 million, and the number of females was 56.81
million. By 2010, some of those children will have died. Absent a large inmigration of children, the number of males and females ages 10–14 should be
lower. The 2011 census data that we use for 2010, however, shows 68.19 million
males and 61.42 million females in the 10–14 age cohort. That’s a lot more young
teenagers alive in 2010 than toddlers reported in 2000. Where did they come
from? Has the Indian census gotten better at counting them all? Did they
immigrate in legally or illegally? Were children missed by the census or
deliberately underreported in 2001 (2000 data)? We don’t know, but the CBR
spikes in 2015 in the business-as-usual 2.6 TFR scenario in part because of the
large cohort of 10–14-year-olds who move up to 15–19-years-old in 2015 and
begin having children.
This CBR spike then dampens out over time as we simulate forward. However,
the CBR spike in 2015 becomes more exaggerated as the assumed TFR is made
larger. In addition, the higher you assume the TFR to be, the more this spike gets
repeated every 20–25 years into the future. With high TFR assumed, there will be
a series of gradually dampening baby booms going forward.