2. Stage 3 - Late
Expanding
Birth Rate starts to fall.
Death Rate continues to
Stage 1 - High Fluctuating fall. Population rising.
Stage 2 - Early Expanding
Birth Rate and Death rate are Reasons:
Birth Rate remains high. Death Rate is
both high. Population growth is â˘Family planning
falling. Population begins to rise steadily.
slow and fluctuating. available
Reasons
Reasons: â˘Lower Infant Mortality
Death Rate is falling as a result of:
Birth Rate is high as a result of: â˘Improved health care (e.g. Smallpox Rate
â˘Lack of family planning â˘Increased
Vaccine)
â˘High Infant Mortality Rate: â˘Improved Hygiene (Water for drinking mechanization reduces
putting babies in the 'bank' need for workers
boiled)
â˘Need for workers in agriculture â˘Increased standard of
â˘Improved sanitation
â˘Religious beliefs â˘Improved food production and storage living
â˘Children as economic assets â˘Changing status of
â˘Improved transport for food
Death Rate is high because of: â˘Decreased Infant Mortality Rates women
â˘High levels of disease Typical of Britain in
Typical of Britain in 19th century;
â˘Famine late 19th and early
Nigeria, Peru, Sri Lanka, Kenya
â˘Lack of clean water and 20th century; China,
sanitation Cuba, Australia
â˘Lack of health care
â˘War
â˘Competition for food from Stage 4 - Low
predators such as rats Fluctuating
â˘Lack of education Birth Rate and Death
Typical of Britain in the 18th Rate both low.
century and the Least Population steady.
Economically Developed Typical of USA,
Countries (LEDC's) today e.g. Canada, Japan, Britain
Ethiopia and Bangladesh.
3. Stage 5
The Slow Declining Stage
⢠In some societies it may be possible to
add a stage 5 where the birth rate has
fallen and because of the increasing
average age of the population, the death
rate has risen.
⢠At this stage, the population begins to
decline
4. Uses of the DTM
⢠The model has a number of uses its main being having the ability to predict the
population of the country and how it could possibly change over time.
⢠By doing this the model helps us to make comparisons between countries
especially LEDCs and MEDCs. Comparisons can also be made in how a
countryâs economic and social conditions might effect its population.
⢠The ability to predict is very valuable because often it can tell us about the fertility
rates and whether they are at replacement level or extremely high and give the
country a chance to take some action.
⢠The stages have been proven to be effective in a number of countries, an
example is the UK. This shows us that the model can be considered reliable.
⢠With a model like this we are able to make more complex models. Each stage is
vital to be able to predict the world populations and future changes that may
occur. It also allows us to see how different factors affect birth and death rates
and for what reasons. We will be able to base these reasons on past factors such
as the advanced technology for better health care and improved education
services. This will mean over time we will be able to make a more advanced
model based on this one.
5. Limitations of the DTM
⢠The limitations of the DTM are best
understood by looking at the
origins of the model. It is essentially
a descriptive analysis of the
evolution of the population of the
U.K. So it has limitations in parts of
the world where there has been a
different economic, political and
social background to that in the UK.
6. ⢠The influence that countries may have on each other is not accounted for in the DTM. War,
for example, can have big effects on the population of a country, because increased death
rates and a lower birth rate would occur, causing a rapidly decreasing total population.
⢠It is also possible that the model is wrong in some cases and that some countries will not
pass through all the stages. In LEDCs, countries are mainly in stage two and entering stage
three but until their life styles change and birth rates are reduced, many countries will
remain in these stages and their total population will continue to rapidly increase. Often in
these countries stage three is missed out altogether.
⢠The model does not give any type of time scale for the length of time it takes to pass
through a stage. This can be important because a country could be stuck in a certain stage
for example stage two, here the country would continue to grow and cause over population.
⢠No numbers are given in any of the stages on the model and so therefore a country can be
very varied in population numbers. This can cause problems in predictions for a country.
⢠Reasons are not always given for birth rates or death rates dropping. These will vary from
country to country.
⢠The model is often presented with only four stages but already there are countries that
would fit into a fifth stage, for example, Italy, which is experiencing a declining birth rate
below its death rate. The birth rates here are not at replacement level and so therefore the
population is slowly decreasing.
⢠The DTM does not include migration it therefore does not always tell us that the population
has dropped or risen because of people leaving or entering the country. These figures can
have a major effect on a population.