Transcript The Demographic Transition Model

The Demographic Transition
Model
Along with the
Fertility Transition Theory
And
The Epidemiologic Transition
• Conceived by Frank Notestein 1945.
• Model of population change based
upon effects of economic development.
• Based on the experience of the
Western world, it was used for decades
as a model to predict what should/would
happen to developing countries
eventually.
• All countries pass through four stages
to a state of maturity.
http://www.uwec.edu/Academic/
Geography/Ivogeler/w111/demmo
del.htm
Rapid Growth in Cape Verde
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
Chile entered stage 2 of the demographic transition in the 1930s, and it
entered stage 3 in the 1960s.
Low Growth in Denmark
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.
Stage 1: High steady birth rates and high but
fluctuating death rates. Therefore, low natural
increase rate. Two rates are approximately
equal. The death rate fluctuates due to war
and disease. Low income, agricultural society
(agricultural revolution). Birth rates are high to
off-set the high death rates.
Stage 2: Dramatic decline in death rates; high
birth rates. Onset of industrialization and
related health and medical advances. Birth
rates are slow to respond, especially in the
developing world. Key stage for growth.
• Population explosions occur when the birth
rates are high and the death rates start to
decline.
• Death rates began to drop due to better
health care, better food supply, a decrease in
wars, better sanitation/hygiene
• More people reached child bearing age.
• So while the death rate went down, the birth
rate remained high, the gap (Natural Increase)
between them increased.
• The wider and longer the gap continued the larger
the population grew
• In a developed country (industrial revolution) the
birth rates eventually started to slow down, it even
spread out due to oversea empires and migration.
Interesting that early migration was people from
MDCs going to other MDCs (Britain, Germany,
France to USA and Canada). Urbanization led to a
decrease in birth rates as well.
• In a developing country the drop in birth rates took a
long time. In some countries the birth rates still
haven’t dropped.
• Children remained (remain) an economic asset, not
a liability in the developing world.
Stage 3: Low death rates; declining birth
rates, due to voluntary decisions to reduce
family size aided by improved
contraception. Related to improved
standard of living. Natural increase rate
falls.
Stage 4: Low steady death and birth rates.
Low natural increase rate, similar to Stage
1. Most developed countries are in this
stage. Low death rates; declining birth
rates. Zero Population Growth. Death rates
higher than birth rates – negative growth.
• So, in summary, the argument that is
extracted from the demographic transition
model is that since the developed countries
underwent a dramatic change that resulted in
lower rates of population growth, so should
the developing nations, and their fertility rates
would also fall.
“Development is the best form of birth
control.” or is it???
However ….
This demographic transition has not
occurred uniformly geographically.
Some areas are in Stage 4 and some areas
are in Stage 2.
Times have changed since the developed
world went through the demographic
transition.
Therefore, can we use the ‘dtm’ as a
predictive tool? Can we assume that the
passage from 3rd to 4th stage will happen
over time?
From the evidence of modern experience, it
seems “no”.
Conditions are different:
• Prospects for industrialization are
questionable.
• Globalization is bringing ‘instant’
development to some countries.
• Reductions in death rates are a result in
some countries of diffusion of technology
and aid from the developed world.
• It’s one thing to introduce death control,
another to introduce successful ways to
reduce birth rates
• There is evidence to suggest that the
fertility rates are declining as in the 3rd and
4th stage of the demographic transition
model, but for very different reasons.
This is known as the Fertility Transition
Theory.
Remember Fertility means the number of
children that a women will have during her
child bearing years (15 to 45 on average).
The Fertility Transition Theory
• Fertility is declining in the developing world
at a rate which exceeds the rate of decline
that was experienced in the developed world.
• It seems to be related directly to the extent
to which modern contraceptives are
employed.
• Education is not a prerequisite for using
contraception.
Diverging Trends in Fertility Reduction
Average number of children per woman
8.2
7.0
6.7
6.9
6.6
7.0
6.3
6.0
5.8
5.5
5.1
4.3
3.5
3.3
3.0
2.4
Bangladesh
Egypt
India
Indonesia
2.4
2.3
Iran
1950-1955
Nepal
Pakistan Turkey
2000-2005
Source: United Nations, World Population Prospects: The 2002 Revision (medium scenario), 2003.
© 2003 Population Reference Bureau
Yemen
• Information about contraception is now
widespread due to mass media.
• Appeal for large families has fallen due to
rising status of women (Empowerment).
• The Developing world is now experiencing
population issues and agricultural problems
that once did not exist. In the past there
would be drought and famine, but it would be
cyclical, today it is happening all the time.
• In summary, the Fertility Transition Theory
asserts that while economic development
can create a climate conducive to
reductions in fertility, it is a change in
cultural attitude about large families and a
willingness to use contraception that is the
key, along with the availability of the
contraception and the empowerment of
women.
• Development is not the best form of
contraceptive; rather contraceptives are the
best form of contraceptive.
• This is why the issue of women’s issues
have become so important.
• But what are some of the obstacles to the
more widespread use of contraception?
• Opposition to birth control and family
planning.
• The manufacture and distribution and
education about their use of contraceptives
is expensive.
• Religion can block birth control programs.
Catholic Church and some others.
• Low status of women: lack of political and
economic rights; lack of access to education.
• Preference for male children in some areas.
• Fertility rates are lower in urban societies,
and much of the developing world is still rural.
• Anti-U.S. governments see contraception as
an American plot to control their country,
culture and religion.
The Epidemiologic Transition
- The distinct causes of death in each
stage of the Demographic Transition.
- Epidemiology is the branch of medical
science concerned with the incidence,
distribution and control of diseases that
affect a large number of people – growing
field ‘Medical Geography’
Stage 1: Stage of Pestilence and Famine.
- Infectious and parasitic diseases - principal
causes of death. Malthus: “Natural checks”.
Eg. Black Plague.
Stage 2: Stage of Receding Pandemics
- A pandemic is a disease that occurs over a
wide geographic area and effects a very high
proportion of the population.
- Improved sanitation, nutrition and medicine
during the industrial revolution reduced the
spread of infectious diseases. Less people
die.
- Death rates begin to drop but not right away.
- Cholera was a big disease in stage 2, especially
in the urban areas – remember urban is new at this
stage.
Stage 3 and 4: Stage of degenerative and
human created diseases.
- Infectious diseases decrease – vaccines take
care of polio.
- Disorders due to aging increase – cardiovascular
diseases (heart attacks) and cancer are important.
The emergence of a Stage 5:
- New strains of viruses and bacteria – the avian
flu and SARS and of course AIDS. A come back of
older viruses such as Malaria and Tuberculosis
are also a characteristic of this stage.
- Improved travel around the globe is one cause,
another is the resistance and adaptation of
diseases to anti-biotics. Another cause is the
increase in poverty and lack of sanitation in an
increasing urban world.
- Fear of Terrorism using a disease as a weapon
should be mentioned – Eg. Smallpox.
Tuberculosis Death Rates, 2000
The tuberculosis death rate is a good indicator of a country’s ability to invest in
health care. TB is still one of the world’s largest infectious-disease killers.
SARS Infections in China, 2003
China had 85 percent of the world's SARS cases in 2003. Within China, the
infection was highly clustered in Guangdong Province, Hong Kong, and Beijing.
HIV/AIDS Prevalence Rates, 2002
The highest HIV infection rates are in sub-Saharan Africa. India and China
have large numbers of cases, but lower infection rates at present.
The End!