The DTM describes a sequence of changes in the
relationships between birth and death rates.
The model was produced using changes in the natural
increase in several countries in Western Europe and
It explains the transformation of countries from having
high birth and death rates to low birth and death rates.
In developed countries this transition began in the 18th
century and continues today.
Less developed countries began the transition later and
many are still in earlier stages of the model.
• Birth Rate
• Death Rate
• Natural Increase
• Population Steady
Birth Rate is high bc of:
• Lack of family planning
• High IMR: putting
babies in the 'bank'
• Need for workers in
• Religious beliefs
• Children as economic
Death Rate is high bc of:
• High levels of disease
• Lack of clean water and
• Lack of health care
• Competition for food
• Lack of education
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; Nigeria
Birth Rate remains high. Death Rate is falling. Population
begins to rise steadily.
Reasons behind birth and death rate falling:
• Family planning available
• Lower Infant Mortality Rate
• Increased mechanization reduces need for workers
• Increased standard of living
• Changing status of women
Birth Rate starts to fall. Death Rate continues to fall.
Impacts and Consequences of
Four Stages Impacts
1. Very Low Growth
2. High Growth
3. High but Slowing Growth
4. Low Growth
Some now see a fifth stage
5. ??? Decline sets in ????
Factors That Change over the
• Family Size
• Infant Mortality & Fertility
• Family Economics
• Status of Kids
• Gender Roles
• Health Conditions
• Transportation Facilities
• Child Deaths
• Population Size
Demographic Trap –Example
Sudan(Failed State?-----Classic Case)
It has developed far enough economically and socially
to reduce mortality, but not far enough to quickly
As a result, women on average have four children,
double the two needed for replacement, and the
population of 41million is growing by over 2,000 per
Under this pressure, Sudan is breaking down.
• It does not include the influences of migration
• It assumes that all countries will go through the
• There is no time scale
• Reasons for changing birth rates and death rates are
very different in different countries
Limitations of DTM
Limitations of the model
• The model was developed after studying the
experiences of countries in Western Europe and
North America. Conditions might be different for
LEDCs in different parts of the world.
• The original model doesn't take into account the
fact that some countries now have a declining
population and a 5th stage.
A characteristic shift in the disease pattern of a
population as mortality falls during the demographic
transition: acute, infectious diseases are reduced,
while chronic, degenerative diseases increase in
prominence, causing a gradual shift in the age pattern
of mortality from younger to older ages
• Pestilence (infections) & Famines
– Infections & Nutritional Deficiencies
• Receding Pandemics
– Improved sanitation, Dec infections, Inc Diet (salt), inc Aging
– Developing Countries
• Degenerative & Man made Diseases
– Inc aging, Lifestyles related to high SES, (diet, activity,
– Countries in transition
• Delayed degenerative & emerging infections
– (Hybristics) The term ‘hybris’ refers to excessive self-confidence
or a belief of invincibility. During the hybristic stage, morbidity
and mortality are affected by man-made diseases, individual
behaviours, and potentially destructive lifestyles.
– Reduced risk behaviors (Health promotion and prevention)
– New treatments
– Western countries
Demographic Transition Egeo 312 45
Declining World Mortality Rates Map
At the end of the second and the beginning of the third stages of
the demographic transition, death rates declined.
Where did they first decline and where did they last decline?
Created by Ingolf Vogeler on 1 February 1996 http://www.uwec.edu/geography/Ivogeler/w111/dempop.htm
Demographic Transition Egeo 312 47
Ratio of non-working population to working age
Non-Workers are the young and aged retirees
– young are usually 15 yrs old and below
– retirees are usually 64 yrs old and above
Demographic Transition Egeo 312 48
Dependency Ratio now
and in the future based
on lots of kids but few
However note how the
young population is
expected to stabilize
and elderly grow.
1. Replacement rate, the number of births needed to
keep a population at a stable level without
immigration, requires a total fertility of
a. 10. b. 2.1. c. 3.5. d. 5.
3. Which of the following countries is most likely to
be showing the lowest natural increase rate?
a. Afghanistan b. United States
c. Japan d. Chile
4. Countries with aging populations attempt to
stimulate economic growth to lessen the effect of
rising medical and retirement costs by
a. cutting social security.
b. encouraging increased birth rate.
c. promoting immigration.
d. promoting emigration of the elderly.
5. Demographically, Great Britain experienced a
___________________ in the period from the late
1800s through WWII.
a. population decline
b. rising death rate
c. population explosion
d. rapid birth rate decline
7. The medical revolution has been characterized by
a. Development of new inventions
b. Diffusion of medical practices
c. Increased agricultural productivity
d. Invention of new medicines
8. The average number of births women bear in their
a. total fertility rate b. crude birth rate
c. natural increase rate d. crude death rate
9. A decline in a country’s crude birth rate would
result in an increase in the country’s
a. Doubling time b. Natural increase rate
c. Total fertility rate d. Life expectancy rate
10. The low rate of contraceptive use in Africa reflects
a. low status of women
b. Improving education of women
c. Rapid diffusion
d. A and B
Explain your answers in relation to demographic
1. Why is population growing so fast?
2. Which areas are growing fastest?
3. What effects has this growth had on social and