Transcript Making Population Real






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?
Stage 1
Stage 2
Stage 3
Stage 4
Birth rate
Natural
increase
Death rate
Time
Note: Natural increase is produced from the excess of births over deaths.



Birth Rate and Death rate are both high. Population growth is slow and
fluctuating.
Reasons
Birth Rate is high as a result of:






Death Rate is high because of:








Lack of family planning
High Infant Mortality Rate: putting babies in the 'bank'
Need for workers in agriculture
Religious beliefs
Children as economic assets
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
Typical of Britain in the 18th century and the Least Economically Developed
Countries (LEDC's) today.


Birth Rate remains high. Death Rate is falling.
Population begins to rise steadily.
Reasons
 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


Birth Rate starts to fall. Death Rate continues to
fall. Population rising.
Reasons:






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.

Birth Rate and Death Rate both low. Population
steady.
 Economy is settled
 Fully developed Middle Class
 Political stability

Typical of USA; Sweden; Japan; Britain
What population patterns are revealed in the
traditional Demographic Transition model?
Assignment:
 Construct a graph of birth and death rates
in England from 1750-2000.
Births/Deaths per 1,000
60
50
40
Sweden
Birth Rate
Mexico
Birth Rate
30
Death Rate
20
Death Rate
10
0
1750 1775 1800 1825 1850 1875 1900 1925 1950 1975 2000
Sources: B.R. Mitchell, European Historical Statistics 1750-1970 (1976): table B6; Council of Europe, Recent
Demographic Developments in Europe 2001 (2001): tables T3.1 and T4.1; CELADE, Boletin demografico 69 (2002):
tables 4 and 7; Francisco Alba-Hernandez, La poblacion de Mexico (1976): 14; and UN Population Division, World
Population Prospects: The 2002 Revision (2003): 326.




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?

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 MEDCs 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 LEDCs, 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. Initially, the death rate in many British
cities rose, due to the insanitary conditions which resulted from rapid
urban growth, and it only began to fall after advances were made in
medicine. The delayed fall in the death rate in many developing
countries has been due mainly to their inability to afford medical
facilities. 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.
Stage 1
Event
Stage 2
Event
Stage 4 Attitude
Demographic
Transition
Model in
England
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.

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.



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.
This large segment of the
population is the post-World
War II "baby boom." As this
population ages and climbs up
the pyramid, there will be a
much greater demand for
medical and other geriatric
services. An online animated
population pyramid from 1950
to 2050 shows the aging of the
boomers.
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.
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.
Fig. 2-18: Chile entered stage 2 of the demographic transition in the
1930s, and it entered stage 3 in the 1960s.
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.

How many countries are in each of the
following stages of the demographic
transition?
 Stage 1- None
 Stage 2 and 3- majority of countries
 Stage 4- None


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
Thomas Malthus
Neo-Malthusians
Critics of Malthus
Population is growing
faster than Earth’s food
supply
Population increased
geometrically; food supply
increased arithmetically
•Transfer of medical
technology leads to a
rapid increase in
population in poor
countries
•World population is
outstripping a wide variety
of resources
•Wars and civil violence
will increase because of
scarcity of food and other
resources
•Large populations
stimulate economic
growth
• Poverty, hunger, and
other social welfare
problems are a result of
unjust social and economic
institutions
Food production increased more rapidly than
predicted
 Population didn’t quadruple
Population is increasing a slower rate

Fig. 2-20: Malthus predicted population would grow faster than food
production, but food production actually expanded faster than
population in the 2nd half of the 20th century.

What are the two ways to bring birth rates
down?
 Lower birth rates
 Higher death rates

What two strategies have proven successful
to lower birth rates?
 Reliance on economic development
 Distribution of contraceptives
Fig. 2-21: Crude birth rates declined in most countries during the 1980s and
1990s (though the absolute number of births per year increased from
about 120 to 130 million).
Fig. 2-22: Both the extent of family planning use and the methods used vary
widely by country and culture.

This transition occurs as a country undergoes the
process of modernization or economic
development. Less economically developed
countries have higher rates of infectious diseases as
standards of medical care are lower than that found
in more economically developed countries.

In more economically developed countries, more
people die from degenerative diseases as infectious
diseases such as cholera and typhoid are easily
treated, causing more people to die from cancers as
they live longer.

The first transition was from hunting-gathering to
primary food production. During this transition,
infectious and parasitic diseases became prevalent.
The shift to agriculture provides a more sedentary
way-of-life and this creates more opportunities for
contact with infected animals and human waste (i.e.
vectors and vehicles of transmission).

The second epidemiological transition
occurred in modern times with infectious
diseases under control and chronic,
noninfectious, degenerative diseases rising.
This second epidemiological transition is
typically in the wealthy or developed nations.
Developing nations still suffer from infectious
diseases more than chronic diseases.

The stage of generative and human-created
diseases, characterized by a decrease in
deaths from infectious diseases and an
increase in chronic disorders associated with
aging. Two important chronic disorders are
cardiovascular diseases and various forms of
cancer

The stage of delayed degenerative diseases.
The major degenerative causes of deathcardiovascular diseases and cancers. Life
expectancy of older people is extended
through medical advances

The stage of reemergence of infectious and
parasitic diseases. Infectious diseases
thought to have been eradicated or
controlled have returned, and new ones have
emerged.
Fig. 2-23: By mapping the distribution of cholera cases and water pumps in Soho,
London, Dr. John Snow identified the source of the water-borne
epidemic.
Fig. 2-24: The tuberculosis death rate is good indicator of a country’s ability to
invest in health care. TB is still one of the world’s largest infectious
disease killers.
Fig. 2-26: The highest HIV infection rates are in sub-Saharan Africa. India and
China have large numbers of cases, but lower infection rates at
present.