Transcript Ch. 2 Population Sec. 2.3 - Demographic Transition Model

AP Human Geography
Key Issue 2-3
Why Is Population Increasing at
Different Rates in Different
Countries?
Variations in Population Growth
• The Demographic Transition
– 1. Low growth
– 2. High growth
– 3. Moderate growth
– 4. Low growth
• Population pyramids
– Age distribution
– Sex ratio
• Countries in different stages of demographic
transition
• Demographic transition and world population
growth
What is the Demographic Transition?
• The shift from high to low mortality and
fertility through four distinct stages.
• Based on the experience of Western Europe’s
Industrial Age.
• Began by Warren Thompson in 1929.
• Further developed in 1945 by Frank Notestein
• A sign of socio-economic progress?
The Demographic Transition
• Stage 1: Low Growth
– Very high CBR
– Very high CDR
– Very low NIR
• Stage 2: High Growth
– High CBR
– Rapidly declining CDR
– Very high NIR
• Stage 3: Moderate Growth
– Rapidly declining CBR
– Moderately declining CDR
– Moderate NIR
• Stage 4: Low Growth or
Stationary
– Very low CBR
– Low, slightly increasing
CDR
– Zero or negative NIR
• Stage 5?: Stationary
population level (SPL)?
In Depth New Model
Stage 1 - High Fluctuating
 Birth Rate and Death rate are both high. Population growth is slow and fluctuating.
 Reasons
 Birth Rate is high as a result of:
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Lack of family planning
High Infant Mortality Rate: putting babies in the 'bank'
Need for workers in agriculture
Religious beliefs
Children as economic assets
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High levels of disease
Famine
Lack of clean water and sanitation
Lack of health care
War
Competition for food from predators such as rats
Lack of education
 Death Rate is high because of:
 Typical of Britain in the 18th century and the Least Economically Developed
Countries (LEDC's) today.
In Depth New Model
Stage 2 - Early Expanding
 Birth Rate remains high. Death Rate is falling.
Population begins to rise steadily.
 Reasons
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Death Rate is falling as a result of:
Improved health care (e.g. Smallpox Vaccine)
Improved Hygiene (Water for drinking boiled)
Improved sanitation
Improved food production and storage
Improved transport for food
Decreased Infant Mortality Rates
 Typical of Britain in 19th century; Bangladesh; Nigeria
In Depth New Model
Stage 3 - Late Expanding
 Birth Rate starts to fall. Death Rate continues to
fall. Population rising.
 Reasons:
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Family planning available
Lower Infant Mortality Rate
Increased mechanization reduces need for workers
Increased standard of living
Changing status of women
Typical of Britain in late 19th and early 20th century;
China; Brazil.
In Depth New Model
Stage 4 - Low Fluctuating
• Birth Rate and Death Rate both low. Population
steady.
– Economy is settled
– Fully developed Middle Class
– Political stability
• Typical of USA; Sweden; Japan; Britain
In Depth New Model
Stage 5? – Declining Population
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Theoretical
Death Rate exceeds Birth Rate.
Negative NIR
Mostly Eastern European Countries
– Russia
– Belarus
– Germany
– Italy
– Japan
• Many developed countries are predicted to experience
population decline.
– Factor of more elderly than young population in these countries
– Fewer young women who will be entering their childbearing years
– Elderly Support Ratio - The number of working-age people (ages
15–64) divided by the number of persons 65 or older
ELDERLY SUPPORT RATIO
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Is the Demographic Transition Model Still
Useful?
• How well does the classic model work?
• Is it a useful framework for developing
countries?
• Do developing countries need to share the
experiences of Europe and the United States?
• Is the socioeconomic change experienced by
industrialized countries a prerequisite or a
consequence of demographic transition?
Is the model universally applicable?
• Like all models, the demographic transition model
has its limitations. It failed to consider, or to
predict, several factors and events:
– 1 Birth rates in several MDCs have fallen below death
rates (Germany, Sweden). This has caused, for the first
time, a population decline which suggests that perhaps
the model should have a fifth stage added to it.
– 2 The model assumes that in time all countries pass
through the same four stages. It now seems unlikely,
however, that many LDCs, especially in Africa, will ever
become industrialized.
– 3 The model assumes that the fall in the death rate in
Stage 2 was the consequence of industrialization. In
many countries, the fall in the birth rate in Stage 3 has
been less rapid than the model suggests due to religious
and/or political opposition to birth control (Brazil),
whereas the fall was much more rapid, and came earlier,
in China following the government-introduced ‘one
child’ policy. The timescale of the model, especially in
several South-east Asian countries such as Hong Kong
and Malaysia, is being squashed as they develop at a
much faster rate than did the early industrialized
countries.
– 4 Countries that grew as a consequence of emigration
from Europe (USA, Canada, Australia) did not pass
through the early stages of the model.
Population Pyramid
Population Pyramids = graphic device
that represents a population’s age and
sex composition.
Pyramid describes diagram’s shape
for many countries in 1800’s when
was created.
Population Pyramid Overview
• The most important demographic characteristic of a
population is its age-sex structure. Age-sex pyramids
(also known as population pyramids) graphically
display this information to improve understanding
and ease comparison.
• Age-sex pyramids display the percentage or actual
amount of a population broken down by gender and
age. The five-year age increments on the y-axis
allow the pyramid to vividly reflect long term trends
in the birth and death rates but also reflect shorter
term baby-booms, wars, and epidemics.
Population Pyramids
• The shape of a pyramid is primarily determined by the
crude death rate in the community.
• Dependency ratio-the number of people who are too
young or too old to work, compared to the number of
people in their productive years.
• People who are 0-14 and 65-plus normally are classified
as dependents.
• The “graying” of a population refers to the aging of a
community.
• Population pyramids also foretell future problems from
present population policies or practices. Ex. China’s
population policies skewed in favor of males.
Dependency ratio
• Number of people who are too young or too old
to work, compared to the number of people in
their productive years
• Indicates financial burden on a society’s
productive population
• Dependency Ratio = measure of # of dependents –
old and young that each 100 people in productive
years (15 – 64)
© 2013 Pearson Education, Inc.
Sex Ratio
• The number of males per hundred females in
the population is the sex ratio. In Europe and
North America the ratio of men to women is
about 95:100
• In poorer countries the high mortality rate
during childbirth partly explains the lower
percentage of women.
There are three key types
of population pyramids:
Rapid Growth:
This pyramid of
the Philippines
shows a triangleshaped pyramid
and reflects a
high growth rate
of about 2.1
percent annually.
There are three key types
of population pyramids:
Slow Growth:
In the United States,
the population is
growing at a rate of
about 1.7 percent
annually. This growth
rate is reflected in the
more square-like
structure of the
pyramid. Note the
lump in the pyramid
between the ages of
about 35 to 50.
In wealthy countries with very slow rate of
population growth – population is nearly equally
divided - so pyramids have
• Almost vertical sides.
• War can be reflected by showing depleted age
cohorts and male – female disparities.
• The % of a country’s population in each age group
strongly influences demand for goods and services
within that national economy.
• Country with high % of young has high demand for
educational facilities and health delivery services.
There are three key
types of population
pyramids:
Negative Growth:
Germany is
experiencing a period of
negative growth (0.1%). As negative
growth in a country
continues, the
population is reduced.
A population can shrink
due to a low birth rate
and a stable death rate.
Increased emigration
may also be a
contributor to a
declining population.
Population Pyramids in U.S. cities
Countries In Different Stages of
Demographic Transition
Rapid Growth in Cape Verde
Fig. 2-17: Cape Verde, which entered stage 2 of the demographic transition in about
1950, is experiencing rapid population growth. Its population history
reflects the impacts of famines and out-migration.
Moderate Growth in Chile
Fig. 2-18: Chile entered stage 2 of the demographic transition in the
1930s, and it entered stage 3 in the 1960s.
Low Growth in Denmark
Fig. 2-19: Denmark has been in stage 4 of the demographic transition
since the 1970s, with little population growth since then. Its
population pyramid shows increasing numbers of elderly and
few children.
2.5 The Demographic Transition
POPULATION PYRAMID AND DEMOGRAPHIC TRANSITION
FOR CAPE VERDE (LEFT), CHILE (CENTER), DENMARK (RIGHT)
© 2013 Pearson Education, Inc.
Census taking in China
Demographic Transition and World
Population Growth
• How many countries are in each of the
following stages of the demographic
transition?
– Stage 1- None
– Stage 2 and 3- majority of countries (i.e. Egypt,
Kenya, India)
– Stage 4- USA, Japan, France, UK
– Stage 5 – Germany?
Two “big breaks” & their causes
• The first break-the sudden drop in the death
rate that comes from technological
innovation
• The second break-sudden drop in the birth
rate that comes from changing social
customs