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Factors That Affect Human Population Size
•
•
Crude birth rate: the number of live birth per 1,000
individuals in one year.
• Crude death rate: the number of deaths per 1,000
individuals in one year.
• The annual rate of population change in percentage
is:
CBR – CDR
% change in population = 1,000
x 100%=
•
14-8
%=
1000
•
•
•
World 2005=1.21%
Europe 2005= -.7%
Developing = 1.8%
X100% = .6%
In USA, this number
does not include
immigration
US and world population growth rate
•
•
•
•
U.S. population growth rate in 1965 was
2%, now in 2009 it is .9% (including
migration)
The U.S. is the third most populous country
in the world. 306 million
World population 6.8 billion
Doubling time = rule of 70 : 70 divided by
the population growth rate equals the
doubling time in years
_70_
.97
= 72
years
In the world there are 2.5
babies born for every
one heart beat
Average crude birth rate
Average crude death rate
World
22
9
All developed
countries
11
10
All developing
countries
25
9
Developing
countries
(w/o China)
29
9
Fig. 11.2a, p. 239
Africa
38
14
Latin
America
24
6
Asia
22
8
Oceania
18
7
United
States
15
9
North
America
14
9
Europe
10
11
Fig. 11.2b, p. 239
Population Growth Rate
Annual world
population growth
<1%
1-1.9%
2-2.9%
3+%
Data not
available
Fig. 11.3, p. 240
% population growth rate - worldwide
Growth rate (percent)
2.5
2.0
1.5
1.0
0.5
0.0
1950
1960
1970
1980
1990
2000
2010
2020
2030
2040
2050
Year
Fig. 11.4, p. 240
China
1.26 billion
1.4 billion
India
1 billion
1.4 billion
USA
Indonesia
Brazil
276 million
338 million
212 million
273 million
170 million
221 million
Pakistan
Russia
Bangladesh
Japan
151 million
227 million
145 million
137 million
128 million
177 million
127 million
121 million
Nigeria
123 million
205 million
Fig. 11.5, p. 241
2000
2025
Asia
3.7 billion
4.7 billion
Europe
728 million
714 million
Africa
800 million
1.3 billion
Latin
America
518 million
703 million
North
America
306 million
374 million
Oceania
31 million
39 million
2000
2025
Fig. 11.6, p. 241
Measuring Global Fertility Rate
•
Replacement fertility rate: the number of
children a couple must bear to replace
themselves
• 2.1 for developed countries
• 2.5 for developing countries
• Even after lowering fertility rates to
replacement level, it will take 50 – 60
years for the population to stabilize
Total fertility rate (TFR):
an estimate of the number of children a women will
have during her child bearing years.
• Worldwide TFR = in 2009 2.6
• 1.7 in developed countries, 3.85 in developing
countries, can be a high as 6 in some countries like
Africa.
• Europe TFR = 1.5
At a TFR of 2.9
• USA TFR = 2.1
with no limits to
• Hispanic= 2.9
population
• Asian = 1.9
growth, in 150
• Black = 2.2
years there will
• White = 1.8
be 296 billion
people on this
World
5 children per women
2.9
Developed
countries
2.5
1.5
Developing
countries
6.5
3.2
Africa
6.6
5.3
Latin
America
5.9
2.8
Asia
5.9
2.8
Oceania
3.8
2.4
North
America
3.5
2.0
Europe
2.6
1.4
Fig. 11.7, p. 241
1950
2000
Births per woman
<2
4-4.9
2-2.9
5+
3-3.9
Data not
available
Fig. 11.8, p. 242
Population Estimates for 2050
12
11
Population (billion)
10
9
8
High
High
10.7
Medium
Low
Medium
8.9
7
6
Low
7.3
5
4
3
2
1950 1960 1970 1980 1990 2000 2010 2020 2030 2040
Year
2050
Fig. 11.9, p. 242
. Fertility In The U.S.
•
•
•
•
•
306+ million people in the U.S.
Peak TFR was 3.7 in 1957 during the
baby boom
In 2009 growth rate was .97 %, 56% of
this was babies being born and 44%
was immigration.
In 2000 there were 7.1 million babies
born, 900,000 legal immigrants, 300,000
illegal immigrants
By 2050 the U.S. population is expected
to reach 439,000
. Fertility In The U.S.
•
The 4 main reasons for such high growth
in the U.S.
1. Large numbers
of women
Teen Pregnancy
15-19 from the baby
boom are Total
stillper
in1000
childbearing
years.
births
There has been
World = a
50large increase in
potential mothers
in recent years,
USA = 53
although TFR
LDC =has
112 remained stable.
MDC =24
2. High # of unmarried
women bearing
children Europe = 5.8
= 3.5 ethnic groups
3. High TFR inJapan
certain
4. High levels of immigration
California Fertility
1. most populous state in the nation
2. 34 million people, expected to rise to 39
million by 2020
3. Since 1985 the CA TFR rose from 1.9 to
2.5 because immigrants have high
fertility.
• Increases in population size has caused
wetland destruction, air pollution, more
endangered species than any other
continental state except for Texas.
TFR in the US
4.0
Births per woman
3.5
3.0
2.5
2.1
2.0
1.5
1.0
0.5
0
1920
1930
1940
1950
1960
1970
1980
1990
2000
2010
Year
Fig. 11.10, p. 243
Births per thousand population
32
30
28
26
24
22
20
18
16
14
0
1910
World War II
Demographic
transition
1920
Depression
1930
1940
Baby boom
1950
1960
Baby bust
1970
Echo baby boom
1980
1990
2000
2010
Year
Fig. 11.11, p. 243
Highly Effective
Extremely Effective
Total abstinence
Sterilization
Hormonal implant
(Norplant)
100%
99.6%
98%
IUD with slow-release
hormones
98%
IUD plus spermicide
98%
Vaginal pouch
(“female condom”)
97%
IUD
Condom (good brand)
plus spermicide
Oral contraceptive
95%
95%
93%
Fig. 11.12a, p. 244
Effective
Moderately Effective
Cervical cap
89%
Condom
(good brand)
Spermicide (creams,
jellies, suppositories)
75%
Rhythm method (daily
temperature readings)
74%
84%
Withdrawl
74%
Rhythm method (Billings,
Sympto-Thermal)
84%
Condom
(cheap brand)
Vaginal sponge impregnated with spermicide
83%
86%
Diaphragm
plus spermicide
Spermicide (foam)
70%
82%
Unreliable
Douche
Chance
(no method)
40%
10%
Fig. 11.12b, p. 244
Developed Countries
Rate per 1,000 people
50
40
Rate of
natural increase
30
Crude
birth rate
20
Crude
death rate
10
Rate of natural increase = crude birth rate = crude death rate
0
1775 1800
1850
1900
Year
1950
2000
2050
Fig. 11.13a, p. 245
Developing Countries
50
Rate per 1,000 people
Crude
birth rate
40
Rate of
natural
increase
30
Crude
death rate
20
10
0
1775 1800
1850
1900
Year
1950
2000
2050
Fig. 11.13b, p. 245
Factors that Influence Birth and Fertility
Rates
• Average level of education and affluence (high
education=low TFR)
• Importance of children as part of the labor force
• Urbanization (urbanization=lower fertility rates)
• Cost of raising and educating children
• Educational and employment opportunities for women
• Infant mortality rate (high infant mortality rate=high TFR)
• Average age at marriage (younger=more kids)
• Availability of pension plans (pension plan=less kids)
• Availability of legal abortions
• Availability of birth control
• Religious beliefs, traditions, norms
• Economic rewards and penalties for bearing children (Like
China)
Factors that Influence Death Rates
• The rise in world population in the last 100
Mortality
years is not aInfant
result
of huge increases in CBR,
Deaths per 1000
but is due to decreases
in CDR
birthsfood supplies, medicine,
• This is due to Live
better
betterLife
sanitation,
Expectancy
USA =and
6.9 safer water
World
= 66.5
• The two
most
useful
indicators of overall
Europe
= 4.5
USA
Male ==75.2,
health
of=a77.9,
population:
World
57 Female = 80.6
• Life expectancy: Europe, 79 U.S., Average 76
LDC = 97
developed, 52 developing
MDC = rates:
7.7
• infant mortality
# of babies out of every 1,000
born that die before the age of one (this is the single
most important factor to measure a society’s overall
quality of life)
Infant deaths per 1,000
live births
<10
10-35
36-70
71-100
100+
Data not
available
Fig. 11.14, p. 246
Deaths under age 1 per 1,000 live births
110
100
90
80
70
60
50
40
30
20
10
0
1920
1930
1940
1950
1960
1970
1980
1990
2000
Years
Fig. 11.15, p. 246
Migration
• Voluntary – provides migrant labor
• Involuntary – 25 million environmental refugees
• Only 1% of annual population growth in
developing countries is absorbed by developed
countries
• Immigration in the U.S.
• 11-12 million illegal immigrants in the U.S.
• 35 million legal
• 75%, 90% if illegal immigrants are counted,
of them are in California, Illinois, New York,
New Jersey, Texas, and Florida
• The U.S. wants to slow legal and illegal
immigration to slow population growth
Number of legal immigrants (thousands)
2,000
1,800
1,600
1,400
1907
1,200
1,000
1914
New laws
restrict
immigration
800
600
400
Great
Depression
200
0
1820 1840 1860 1880 1900 1920 1940 1960 1980 2000 2010
Year
Fig. 11.23, p. 250
Pros
• Often take jobs natives won’t do
• They increase the supply of available
goods
• They boost economy by buying goods
• They pay taxes
Cons
• Work for lower wages and take jobs from
Natives
• States bear the costs and the federal
government collects all the taxes
• Laws to catch illegal immigrants do not
work
Population Age Structure
• Age structure diagram: shows the proportion of
the population at each age level
• prereproductive: 0-14
• reproductive: 15-44
• post-reproductive: 45+
•
The percentage of the population at each age
level
• # of women of reproductive age (50% of
world’s women)
• # of women under the age of 15 (29% of
world, 42% of Africa, 32% developing,
17% developed)
• The more women under age of 15 the more
momentum for growth
• Youthful age structures lead to high
unemployment rates
Male
Female
Male
Rapid Growth
Guatemala
Nigeria
Saudi Arabia
Ages 0-14
Female
Slow Growth
United States
Australia
Canada
Ages 15-44
Ages 45-85+
Fig. 11.16a, p. 247
Male
Female
Male
Zero Growth
Spain
Austria
Greece
Ages 0-14
Female
Negative Growth
Germany
Bulgaria
Sweden
Ages 15-44
Ages 45-85+
Fig. 11.16b, p. 247
Declining Population
• If the decline is slow a country can
manage
• If decline is rapid, there is a larger
number of older people putting strains on
medical, social security, and public
services, with less young people to pay
for it.
• Also less young people mean smaller
military.
AIDS Tragedy
• Between 2000 and 2005 aids will kill 278
million people (almost the size of the US)
• Kills young adults which support the
young and the old. In some African
countries as many as 39% of the
population is affected.
• Analysts call for financial assistance and
education to slow this down. Should we
intervene?
85+
80-85
Male
75-79
Female
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 (millions)
Fig. 11.17a, p. 247
85+
80-85
Male
75-79
Female
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 (millions)
Fig. 11.17b, p. 247
United States (highly developed)
Population
(2000)
276 million
170 million
123 million
Brazil (moderately developed)
Nigeria (less developed)
Population
projected
(2025)
Infant
mortality
rate
338 million
221 million
205 million
7
38
77
Life
expectancy
77 years
68 years
52 years
Fertility
rate (TFR)
2.1
2.4
6.0
%Population
under
age 15
% Population
over
age 65
Per capita
GNP
(1998)
21%
30%
44%
13%
5%
3%
$29,240
$4,630
$300
Fig. 11.18, p. 248
Age structure can be used to predict population
changes.
• For example: baby boomers create changes
in population dynamics as they move
through the age structure. They create
competition for jobs, dominate demands for
goods and services and have political
control. As they age their needs become a
burden to the baby bust generation
(genration x). Echo-boom generation 19772000 largest generation ever
Age
Age
Females
Males
1955
4
12
16
20
8
8
20
16
12
Females
4
1985
4
Millions
Males
24
12
16
20
8
8
16 20
12
24
4
Millions
Fig. 11.19a, p. 248
Age
Age
Females
Males
4
1955
8
8
4
12
16
20
Millions
24
16 20
12
Females
Males
20
4
2035
24
12
16
20
8
8
16 20
12
20
4
Millions
Fig. 11.19b, p. 248
Reducing Births
PROS
• better than raising death rate
• we already fail to provide basic necessities for one-fifth
of the world
• over pop. Is the main reason for environmental
degradation and resource over consumption
• technology is the key to economic power, not more
people
• freedom to reproduce should only apply if it does not
reduce the quality of other peoples lives
CONS
*people live longer
*some people believe that the world can support millions
more
*people are our most valuable resource
Births and Economic Development
1. demographic transition = hypothesis of population change.
As countries become more industrialized, first their death rates, then
birth rates decline. This is done in 4 stages.
a. preindustrial stage - harsh living conditions contribute to high
birth rate & death rate (little population growth)
b. transitional stage - industrialization begins, food production
rises, health care improves, death rates drop, births remain
high, and population grows.
c. industrial stage - industrialization is widespread, birth rate
drops & approaches death rate (due to birth control) decline in
infant mortality, increased job opportunities for women, high
cost of raising children.
d. postindustrial stage - birth rates decline further = ZPG until
the population growth rate decreases, shift to a sustainable
form of economic development. (Most Western European
countries are in this stage = 12% of the world’s population.
2. Some developing countries may have difficulty making the
demographic transition because they lack capital and resources to
move to stage 3 or 4.
Stage 1
Preindustrial
Stage 2
Transitional
Stage 3
Industrial
Stage 4
Postindustrial
High
70
Relative population size
Birth rate and death rate
(number per 1,000 per year)
80
60
Birth rate
50
40
30
Death rate
20
10
Total population
0
Low
growth rate
Increasing Growth
growth rate
Very high
growth rate
Decreasing
growth rate
Low
Low
growth rate
Zero
growth rate
Negative
growth rate
Time
Fig. 11.26, p. 255
Family Planning & Birth Reduction
= provides educational and clinical services to help
couples choose how many and when to have children.
a.
Family planning is responsible for a 40% drop in fertility rates
in developing countries.
b. helps to reduce the need for social services.
c. may reduce legal and illegal abortions.
d. coupled with prenatal care & health services, family planning
can reduce the risk of childbearing.
e. reduces the birth and fertility rates in populous countries such
as China, Indonesia, Brazil, & Bangladesh.
1. there has been a 6-fold increase in the use of contraceptives in the
last 2 decades for married women.
2. couples see fewer benefits of large families due to lack of available
land, unstable farming conditions, extensive flooding &
government supplied mass media messages.
(U.S. has 1/5 of the abortions -242,000/yr)
Economic rewards & penalties for reduced
births
1. payments for using contraceptives or
sterilization (either to women or their
doctors).
2. penalize couples for more than 1 or 2
children (raise their taxes, charge other
fees, or eliminate income tax deductions
for third child, loss of health care
benefits, food allotment, job options.
Empowering Women
1. women with an education & a job
outside the home have fewer children.
2. women work 2/3’s of all hours worked
and receive 1/10 of the world’s income &
own less than 2% of the world’s property.
3. In most developing countries, women
don’t have the legal rights to own land or
borrow $.
4. women make up 70% of the world’s
poor & 2/3’s are illiterate.
Reducing population growth
• Help countries develop and implement national
population policies UNPFA
• Provide universal access to family planning
• Reduce poverty
• Provide better healthcare and nutritious food
supplements
• Provide universal education with emphasis on girls
• Improve the status of women
• Nutritious school lunch programs
• Increase the involvement of men in child rearing and
family planning
• Sharply reduce unsustainable patterns of production
and consumption
4:45 A.M.
Wake,
wash, and
eat
5:00 A.M.5:30 A.M.
Walk to
fields
5:30 P.M.3:00 P.M.
Work in
fields
3:00 P.M.4:00 P.M.
Collect
firewood
4:00 P.M.5:30 P.M.
Pound and
grind corn
5:30 P.M.6:30 P.M.
Collect
water
6:30 P.M.8:30 P.M.
Cook for
family and
eat
8:30 P.M.9:30 P.M.
Wash
dishes
and children
9:30 P.M.
Go to bed
Fig. 11.28, p. 256
Number of workers supporting
each Social Security beneficiary
40
1945
41.9 workers
30
20
1950
16.5
10
2075
1.9
0
1945
2000
2050 2075
Fig. 11.20, p. 249
40
Age Distribution (%)
35
30
25
20
15
10
5
0
1950 1970 1990 2010 2030 2050 2070 2090 2110 2130 2150
Year
Fig. 11.22, p. 249
Under age 15
Age 60 or over
Age 80 or over
State of the World
1900
2000
2100
Year
Industrial output
Food
Resources
Population
Pollution
Fig. 11.24a, p. 251
Material Standard of Living
1900
2000
2100
Year
Consumer goods
per person
Services
per person
Food per person
Life expectancy
Fig. 11.24b, p. 251
State of the World
1900
2000
2100
Year
Industrial output
Food
Resources
Population
Pollution
Fig. 11.25a, p. 254
Material Standard of Living
1900
2000
Year
2100
Consumer goods
per person
Services
per person
Food per person
Life expectancy
Fig. 11.25b, p. 254
Male
sterilization
5%
Condom
5%
Pill
8%
No method
43 %
Other
methods
10%
IUD
12%
Female sterilization
17%
Fig. 11.27, p. 255
India
China
Percentage
of world
population
16%
21%
Population (2000)
1 billion
1.3 billion
Population (2025)
(estimated)
1.4 billion
1.4 billion
Illiteracy (%of adults)
47%
17%
Population under age 15(%)
36%
25%
Population growth rate (%)
Total fertility rate
1.8%
0.9%
3.3 children per woman (down from 5.3 in 1970)
1.8 children per woman (down from 5.7 in 1972)
Infant mortality rate
72
31
Life expectancy
GNP per capita
(1998)
61 years
71 years
Fig. 11.29, p. 257
$440
$750