This document discusses the human population challenge from the "Population Bomb" concerns to current worries about a "demographic crisis". It provides global and US population statistics from 1990 to 2010. It also discusses key demographic terms and concepts like total fertility rate, replacement-level fertility, age structure histograms, and components of population change. While some warn of overpopulation, others warn of a crisis due to aging populations in countries with low birth rates. However, the document argues that characterizing population stabilization as a crisis is misleading given constraints on continuous growth. Overall population growth and its social and environmental impacts present complex challenges that defy simplistic analysis.

1. The Human Population
Challenge: From “Population
Bomb” to “Demographic Crisis”

2. The Human Population
Challenge: From
“Population Bomb” to
“Demographic Crisis”
Lecture Series in Quantitative
Sustainability
by
Toni Menninger MSc
http://www.slideshare.net/amenning/
toni.menninger@gmail.com

3. Sept 2011 Global and US population
Population clock: http://www.census.gov/popclock/

4. Sept 2012 Global and US population

5. Jan 2014 Global and US population
Population clock: http://www.census.gov/popclock/

6. US Population
• 315,218,420 January 29, 2013
• 317,444,010 January 29, 2014
• In one year 2,225,590 increase
• 0.7% annual growth rate
Decennial Census: http://2010.census.gov/

7. The Human Population Challenge
Global Population 2012: 7 billion
Growth rate is currently 1.1%
Doubling time = 70 / growth rate = 64 years
Annual increase about 77 million per year
•
US Census International Programs
•
UN Population Division
•
National Geographic Magazine: The World at
seven billion

8. The Human Population Challenge
Global population since AD 1000
7,000,000,000
6,000,000,000
5,000,000,000
4,000,000,000
3,000,000,000
2,000,000,000
1,000,000,000
0
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
Exponential growth?

9. Global population since AD 1000
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
Global population percent growth rates, AD 1000
to present
2
1.5
1
0.5
0
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000

10. Global population percent growth rates, AD 1000
to present
2
1.5
1
0.5
0
1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000
• Population growth has been 0.1% or less for most
of human history
• Sharp increase after 1750 (Industrial Revolution)
and especially after WWII (Green Revolution)
• Growth rates of past century are historical anomaly

11. Population growth rates worldwide
China
United Nations population growth rate estimates for the period
2005–2010 (wikipedia)

12. World Population Cartogram
World Population Atlas: Country areas scaled to population size

13. The Human Population Challenge:
Demographic terms and concepts
China, India and USA are the world’s most populous countries. In
2010, they each completed a decennial population census. The
table shows the census results since 1990, in million:
Census
year
1990
China
India
USA
1,134
847
249
2000
1,266
1,029
281
2010
1,340
1,210
309
Group work (2-3 students)

14. The Human Population Challenge:
Demographic terms and concepts
China, India and USA are the world’s most populous countries. In
2010, they each completed a decennial population census. The
table shows the census results since 1990, in million:
Census year
1990
2000
2010
China
1,134
1,266
1,340
India
847
1,029
1,210
USA
249
281
309
World
5,263
6,070
6,972
China
India
USA
Sum
China
India
USA
Complete the table:
Population change
1990-2000
2000-2010
Fractional change in %
1990-2000
2000-2010
Approx. what percentage of global population do these 3 countries account for?
Approx. what percentage of global population increase do they account for?
What can you conclude about population growth in the 2000s compared to the
1990s: increased - stayed the same - decreased?

15. Demographic terms and concepts
China, India and USA are the world’s most populous countries. Last
year, they each completed a decennial population census. The table
shows the census results since 1990, in million:
Census year
1990
2000
2010
Population change
1990-2000
2000-2010
Fractional change in %
1990-2000
2000-2010
China
1,134
1,266
1,340
India
847
1,029
1,210
USA
249
281
309
World
5,263
6,070
6,972
China
132
74
China
11.6 %
5.8 %
India
182
181
India
21.5 %
17.6 %
USA
32
28
USA
12.9 %
10.0 %
Sum
346
283
Approx. what percentage of global population do these 3 countries account for?
41%
Approx. what percentage of global population increase do they account for? 37%
What can you conclude about population growth in the 2000s compared to the 1990s?
Fractional growth rate declined in all countries
Absolute rate of increase declined dramatically in China,
less so in USA, and reached a plateau in India
Note: growth rates in table are per decade. To annualize percent rates, use logarithmic formula.
E. g. ln(1.215)/10=1.9% for India during 1990s.

16. Demographic terms and concepts
The Demographic Transition
What causes birth rates to fall?

17. Demographic terms and concepts
The Demographic Transition

18. The Demographic Transition
China
Iceland
Mexico
USA
Births per woman since 1960

19. The Demographic Transition
Total Fertility Rate (TFR): average number of children per woman
Replacement-level fertility: an average fertility of slightly more than 2
children per woman

20. Demographic terms and concepts
Components of annual population change in the USA
Growth rate = birth rate – death rate + net migration
Natural increase = growth rate – death rate

21. Demographic terms and concepts
World population growth rate:
• World Birth rate 2013:
• World Death rate 2011:
18.9/1,000 per year
7.9/1,000 per year
How to calculate growth rate?

22. Demographic terms and concepts
World population growth rate:
• World Birth rate 2013:
• World Death rate 2011:
18.9/1,000 per year
7.9/1,000 per year
How to calculate growth rate?
Birth rate – death rate =
(18.9-7.9)/1000
=
11/1000 = 1.1% (per year)

23. Demographic terms and concepts
Why are
death rates
higher in
developed
countries?

24. Demographic terms and concepts
Why are
death rates
higher in
developed
countries?
=> Age
structure

25. Demographic terms and concepts
Age structure histograms
Expansive vs. constrictive age structure
Source: United Nations, World Population Prospects: the 2002 Revision
(2003), found at
http://www.flatrock.org.nz/topics/money_politics_law/boom_moves_along.htm

26. Demographic terms and concepts
Age structure histograms: expansive
A rapidly growing
population has a large
proportion of prereproductive and
reproductive individuals
and relatively few older
people.
Example: West Africa
Almost one third (1.8 billion) of the world’s population is
under 15 years; in Africa, 42% are under 15 years.

27. Age structure histograms
Mexico
Canada
Sweden

28. Demographic terms and concepts
WWII
Age structure histograms
Mexico: highly expansive, rapidly growing
US: somewhat expansive
Germany: constrictive,
starts shrinking

29. Demographic terms and concepts
Age structure histograms: expansive histogram 2009
World population
100
95-99
90-94
85-89
80-84
75-79
70-74
65-69
60-64
55-59
Fem ale Population
50-54
45-49
40-44
35-39
30-34
25-29
20-24
15-19
10-14
5-9
0-4
0
200000000
400000000
A rapidly growing population has a large proportion of
pre-reproductive and reproductive individuals and
relatively few older people.
Almost one third (1.8 billion) of the world’s population is
under 15 years; in Africa, 42% are under 15 years.

30. Demographic terms and concepts
Age structure histograms: constrictive
A stationary or
shrinking population
has a small
proportion of children
and a relatively large
proportion of older
people.

31. Age structure histograms: expansive to constrictive
84 million
128 million
97 million (projection)
Japan's demographic transition
http://www.stat.go.jp/english/data/handbook/c0117.htm#c02

32. A global demographic transition?
World population histogram 2009
100
95-99
Fem ale Population
90-94
85-89
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
0
100000000
200000000
300000000
400000000
World population histogram 2050
(projected)
100
95-99
90-94
85-89
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
Fem ale Population
0
100000000
200000000
300000000
Source: U.S. Census Bureau International Data Base (IDB)
400000000

33. A global demographic transition?
World population histogram 2009
100
Total Fertility Rate (TFR): average
number of children per woman
95-99
Fem ale Population
90-94
85-89
80-84
75-79
70-74
65-69
60-64
Replacement-level fertility: an
average fertility of slightly more than
2 children per woman
55-59
50-54
45-49
Population stabilization requires a
reduction in TFR to 2.1. This will in
the medium run eliminate population
growth.
40-44
35-39
30-34
25-29
20-24
15-19
10-14
5-9
0-4
0
100000000
200000000
300000000
400000000
However, in the short term
population will continue to grow
because of population inertia (e. g.
China). Many fertile females.

34. Factors favoring population growth
• Children are needed in agriculture
• Children are needed to support ageing parents
• Many children can be a symbol of high status
• Demographic transition not yet completed in LDC
→ Sustainable economic development will,
in the opinion of many experts, induce the
completion of the demographic transition
via social change and economic improvement

35. Factors favoring population growth
• Contraceptives not available/too expensive
• Family planning not considered due to cultural/religious reasons
• Unequal social and economic status of women
• Education, employment opportunities for women
lacking/denied
• Lack of reproductive rights
→ Development experts, organizations and (some)
governments promote the empowerment of women
as a means to stabilize population


International Conference on Population and Development
(ICPD) Cairo, 1994
Fourth World Conference on Women, Beijing 1995

36. The Human Population Challenge –
so what?
• Sustainability requires
stabilization of both
population and (per capita)
consumption
• Zero population growth will
eventually happen –
hopefully by benign means
rather than through disease,
war and famine.

37. The Human Population Challenge –
so what?
• There is no scientific
agreement on what the limit
of earth's carrying capacity
might be – estimates range
from 0.5 to 50 billion.
• The closer we get to the
limit, the more difficult it will
be to achieve sustainability
and decent living standards.

38. The Human Population Challenge –
social implications of rapid growth
At the local and regional level, especially in
poor countries, rapid population growth creates
or exacerbates social, economic and
environmental problems and destabilizes
communities (e. g. Congo, Haiti, Pakistan).
Social institutions and vital infrastructure such
as school and health care systems are
overwhelmed, jobs for young adults are lacking,
adequate housing is lacking, natural resources
are overexploited.

39. Population growth highest in poor countries

40. The Human Population Challenge –
beware of oversimplification
• It is simplistic to blame population
growth as the root of global
environmental problems, as some
environmentalists have done (e. g.
Paul Ehrlich, “The Population Bomb”,
1968). Example for Malthusianism
• Equating hunger with overpopulation
is also simplistic. Hunger is in most
cases caused by poverty and
economic inequality, not lack of food
supply.

41. The Human Population Challenge – a
complex issue
• Resource overuse, climate change and other global
environmental crises are overwhelmingly caused by
an affluent minority. There is extreme global inequality.
• However, raising the living conditions of the world's
poorest implies an increased environmental footprint
for billions. The greater the numbers, the more difficult
it will be to balance development and sustainability.
• E. g. China: per capita CO2 emissions one fourth that
of U.S., total emissions now equal to U.S.

42. The Human Population Challenge –
over-population or over-consumption?
It is simplistic to blame population growth as the root
of global environmental problems.
Reading assignment
George Monbiot 2009: "around one sixth of the world’s
population is so poor that it produces no significant
[greenhouse gas] emissions at all. This is also the
group whose growth rate is likely to be highest.“
• I=PAT: Total environmental impact equals population
times affluence times technology
• I=CAT: Impact = consumers times affluence times
technology

43. The Human Population Challenge – a
complex issue
What is "overpopulation"?
→ Term is often used unscientifically. There are no
generally accepted criteria.
Population density
• Many advanced countries (esp. Western Europe and Japan) have
high population density.
• Many poor countries have low population density, with notable
exceptions (e. g. Bangladesh, Haiti).
Again, high population density can exacerbate social and environmental problems in an underdeveloped, rapidly growing country - but it
is rarely the direct cause of such problems (exception: small islands).

44. The Human Population Challenge
Japan over 1000 people per square km
Population density (people per km²) by country, 2006 (wikipedia)

45. The Human Population Challenge

46. The Human Population Challenge – a
demographic crisis?
While some environmentalists warn of
“overpopulation”, there is an opposite viewpoint –
frequently present in the media - that European
and Asian countries with low birthrates are facing
a “demographic crunch”.
These dire predictions usually refer to countries
like Germany, Italy, Japan and South Korea but
there have even been warnings of a “looming
demographic crisis” (Washington Post,
February 28, 2010) or an “underpopulation
crisis” (Slate, March 7, 2006) threatening China,
the world's most populous nation.

47. The Human Population Challenge – a
demographic crisis?
Japan > 1000 people per square km
→ Western Europe and East Asia are already densely populated.
Demographic stabilization in these regions should be welcomed.

48. The Human Population Challenge – a
demographic crisis?
A typical example of the “demographic crisis”
argument:
“The building blocks of Japan's future are
collapsing, in the view of many economists.
Japan has fewer children and more senior
citizens as a percentage of its population
than any country in recorded history, but
the government does little to encourage
childbirth or enable immigration.”
Washington Post, February 3, 2010

49. The Human Population Challenge – a
demographic crisis?
• Japan is the 10th most populous nation (127
million people).
• It has a population density 10 times higher than
the United States (873 per square mile).
• Japan's workforce is highly educated and highly
productive.
• An increase in the share of senior citizens is an
unavoidable consequence of the demographic
transition (unless life expectancy declines). The
alternative would be to continue growing
indefinitely, which is impossible.

50. A demographic crisis due to aging population?
• More retirees need to be
supported through the intergenerational contract.
• Fewer children → in general
more resources are available
for each child
• The working age share of
Japan's population is now
greater than it was 60 years
ago, despite aging.
• In 40 years, one economically active person might have to
support one additional person on average (current ratio 2:1).
Increased productivity, full employment and possibly a higher
retirement age will likely compensate for the increased burden.
• The main challenge is arguably on the level of social values
rather than material resources.

51. “Demographic crisis”: is Japan facing a labor shortage?
The economic problem of every society is to provide (i. e. produce and distribute) the goods and services
required by that society. In every society, there are members that are economically productive and those
that are not (because they are too young, too old, sick, unemployed, etc.) The term Demographic crisis
expresses concern that ageing populations with low birthrates see their share of retirees increase and
the share of economically productive members decline. So the burden of providing for society's
economic needs placed on the economically active population becomes heavier and heavier.
Is the demographic crisis concern valid?
The potential economic product of a society roughly speaking depends on three factors: age structure,
labor force participation rate, and labor productivity. The cohorts between the ages of 15 and 65 are
generally considered the economically active population from which the work force is recruited. The work
force (labor force) participation rate is the percentage of the economically active population that is
actually engaged in economic activity (by some definition). Labor productivity is the average
economic product per worker ("worker" here includes anybody engaging in productive economic
activity).
In the example of Japan, the economically active population share has actually increased between 1950
and present despite ageing. Labor force participation rate has generally increased since WWII in
industrial societies due to increased participation of women. Labor productivity has increased
exponentially since WWII.
It is projected that Japan's economically active population share will somewhat decrease over the next
decades. It doesn't follow that there will be a labor shortage. Increased productivity and/or an
increase in the labor force participation rate can easily compensate for the demographic change.
Increasing demand for labor will lead to increased wages which will lure people into the workforce who
might otherwise choose not to work. Some workers will choose to retire later if they feel well
compensated and well respected.
Most societies today are suffering from high unemployment and a surplus of labor. There is no
evidence that Japan or any other country is facing a looming labor shortage.

52. The Human Population Challenge – a
demographic crisis?
"For three years running, South Korea has
had the world's lowest birthrate... The nohusband, no-baby trend has become a
demographic epidemic in East Asia...
Collapsing birthrates are alarming East Asian
governments, which in coming years will face
a demographic crunch as the proportion of
pensioners rises and the number of workingage adults declines."
Washington Post, March 1, 2010

53. The Human Population Challenge –
popular demographic misconceptions
“Demographic crunch” in South Korea?
→ South Korea – population 48 million - has 15
times the population density of the USA.
Economist Dean Baker (CEPR) comments:
“In standard economic theory, a smaller labor
force will lead to a higher capital to labor ratio,
which will increase productivity. If productivity is
higher, workers can both enjoy higher living
standards and be able to support a larger
population of retirees.”

54. The Human Population Challenge –
popular demographic misconceptions
"Germany also faces a demographic challenge,
managing a population that is not only graying
but shrinking. Last month the government
announced that the population dropped below
82 million for the first time since 1995. That
means fewer people trying to pay off a growing
national debt, with a projected budget deficit of
$118 billion this year."
New York Times, February 11, 2010
→ Statement is a non sequitur: the capacity to pay back the
national debt has nothing to do with population growth, unless
the economy is understood as sort of a “Ponzi scheme”.

55. The Human Population Challenge –
popular demographic misconceptions
"We are living in an age of reversegenerativity. Far from serving the young,
the old are now taking from them. First,
they are taking money. ... the federal
government now spends $7 on the elderly for
each $1 it spends on children."
David Brooks: The Geezers’ Crusade, New York
Times, February 1, 2010
Class discussion

56. Generational
contract or
Generational
warfare?
http://reason.com/archives/2012/07/23/generational-warfare

57. The Human Population Challenge –
popular demographic misconceptions
"the federal government now spends $7 on the
elderly for each $1 it spends on children."
David Brooks, NYT
→ The federal government doesn't fund schools. Most public
spending targeted at children is at the state and local level.
→ Social Security is funded by a dedicated payroll tax.
Retirees have contributed to the fund throughout their
working lives. It is inaccurate to imply that this money is
somehow taken away from children.
→ Old age provision systems such as Social Security are
based on the inter-generational contract. Modern society
arguably cannot function without, or retirees would have to
rely on family support (which would favor large families).

58. The Human Population Challenge –
popular demographic misconceptions
"400 Million People Can’t Be Wrong"
With a fertility rate 50 percent higher than Russia,
Germany, or Japan, and well above that of China,
Italy, Singapore, South Korea, and virtually all of
Eastern Europe, the United States has become an
outlier among its traditional competitors, all of
whose populations are stagnant and seem
destined to eventually decline.
With the mobilization of our entrepreneurs and
supportive government policies, the United States
should be able to exploit its vibrant demography to
assure its preeminence over the next four decades.
Joel Kotkin, Newsweek, April 16, 2010

59. “The United States has become an outlier
among its traditional competitors”

60. The Human Population Challenge –
popular demographic misconceptions
"400 Million People Can’t Be Wrong“?
“Mercantilists [the school of thought that dominated Europe from the 16th
through the 18th century] and the absolute rulers who dominated many states
of Europe saw each nation’s population as a form of national wealth: the larger
the population, the richer the nation. Large populations provided a larger labor
supply, larger markets, and larger (and hence more powerful) armies for
defense and for foreign expansion. Moreover, since growth in the number of
wage earners tended to depress wages, the wealth of the monarch could be
increased by capturing this surplus. In the words of Frederick II the Great of
Prussia, “the number of the people makes the wealth of states.” Similar views
were held by mercantilists in Germany, France, Italy, and Spain. For the
mercantilists, accelerating the growth of the population by encouraging fertility
and discouraging emigration was consistent with increasing the power of the
nation or the king. Most mercantilists, confident that any number of people
would be able to produce their own subsistence, had no worries about harmful
effects of population growth. (To this day similar optimism continues to be
expressed by diverse schools of thought, from traditional Marxists on the left to
“cornucopians” on the right.)” Encyclopedia Britannica

61. Cornucopianism versus Malthusianism
A cornucopian is a futurist who believes that continued
progress and provision of material items for mankind can
be met by similarly continued advances in technology.
Fundamentally they believe that there is enough matter
and energy on the Earth to provide for the ever-rising
population of the world.
Looking further into the future they posit that the
abundance of matter and energy in space would appear
to give humanity almost unlimited room for growth.
The term comes from the cornucopia, the "horn of plenty"
of Greek mythology, which magically supplied its owners
with endless food and drink. The cornucopians are
sometimes known as "Boomsters", and their philosophic
opponents—Malthus
and
his
school—are
called
"Doomsters" or "Doomers."

62. The Human Population Challenge –
popular demographic misconceptions
"400 Million People Can’t Be Wrong“?
• The idea of strength through numbers, and of a
“war of the cradles” between competing
nations, was popular among 18th century
mercantilists.
• Is such a view still appropriate in the 21st
century?
• Is there really a connection between birth rates
and the competitiveness of a modern industrial
society in a globalized economy?

63. Summary: The Human Population Challenge:
Demographic terms and concepts
•
•
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•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
World population as of 2013: 7.1 billion
Birth rate, death rate (mortality), natural change, net migration, growth rate
Population Growth rate = Birth rate - death rate + net migration
World Birth rate 2013:
18.9/1,000 per year
World Death rate 2011:
7.9/1,000 per year
World population growth rate:
(18.9-7.9)/1000 = 1.1% per year
Age structure diagram (“population pyramid”)
Cohorts
Expanding (expansive) – stationary – contracting (constrictive)
Total Fertility, Replacement Fertility
Maternal age, birth spacing
Population Inertia
Life expectancy, infant mortality, child mortality
Demographic transition
Economically active population, labor force, labor force participation rate
Generational contract, Social security
Carrying capacity
Malthusianism, Cornucopianism
Zero Population Growth
I=PAT, I=CAT