The DTM is based on the
demographic changes that
occurred in Britain and
other developed countries
The model was originally,
put into place to show
how the population had
changed in developed
countries
Stages
1 - High Fluctuating
High Birth rate
and Death rate
Birth rate
More children
needed to
provide for the
family
Child mortality is high,
so more children are
born to keep the family
alive
No/little family
planning
Religious
beliefs
No protection
Marry young
Death rate
High
levels of
disease
Bad working conditions
Famine
Poor Hygiene
War
Concave pyramid
shape
Total population is
low
e.g. Remote
groups
2 - Early Expanding
Classic
pyramid shape
Death rate starts to
decrease
Better Education
Better
living
conditions
Better
access to
food
Decreased child
mortality
Better access to
doctors
Infants get
vaccines against
disease
Higher
quality food
Birth rate stays high
Total population
starts to expand
e.g. Kenya
3 - Late Expanding
Pyramid
starts to
even out
Death rate
stay's low
Birth rate starts
to decrease
Country is more
developed, so people
start to focus on work
Less children are
needed to work on
the land
Better healthcare
More children
will survive
Family planning
used
Rapid urbanisation
lessens capacity for
large families
Total population
starts to grow
e.g.
Brazil
4 - Low Fluctuating
Pyramid starts
to become
top-heavy
Total population
stays high
Death rate
stay's low
Birth rate becomes low
Increased desire
for possessions
not family
Couples choice
Feminism/
Women's rights
More women in
education, choosing
careers over family
Very low infant
mortality
e.g. UK, USA
5 - Declining?
Pyramid is
top-heavy
Birth rate stays
low/ starts to
get lower
Family planning
Good health
Late marriages
Improving women's status
Death rate stay's
stable at low
Good
healthcare
Reliable food
source
e.g. Germany
Strengths
The DTM gives a good
generalised picture of
how a population can
change over time
It's timescales are
flexible so more
countries can 'fit' in
with the model
It's easy to compare
countries with only
three indictors
Birth rate
Death rate
Total population
Governments can use the DTM to
predict how the population will change
and make policies based on this
Weaknesses
The original DTM did not have a
Decling stage (5), this was added when
countries like Germany and Japan,
exited the low fluctuating stage (4)
The DTM cannot predict when a
country will reach a certain stage,.
or for how long a country will stay
in a stage for
The original model was
constracted from developed
European countries, the USA
and Japn, so it may not be a
vaild world model
It is based on the experience of
industrialising countries, and therefore may
not be vaild for non-industrialising
countries such as poor, sub-Saharan African
countries
The DTM is a strong descriptive
model, but a weak predictive model
The DTM does not
take into account
migration
Countries in Southern Africa have had their
death rate rise, so that it is similar to stage 1
due to dieases such as HIV/AIDS the DTM
does not help to predict the future of these
countries