The Demographic Transition Model

AS Geography

Learning Objectives

• To learn the concepts behind the DTM• Draw, label and interpret pop’n pyramids• How population pyramids can be used to

predict pop’n change• How various pop’n structures can cause

issues for countries concerned

What is it

• The DTM is a simple diagram• It is a model that shows pop’n change over

time• It is a simplified version of reality• It suggests all countries go through 4 – 5

stages of development• It can be used to predict population

changes over time

Strengths

• It’s dynamic showing changes over time• It describes effectively what happened in

the UK• Many industrialised countries went through

similar stages in Europe and N. America• Some NIC’s (S. Korea, Singapore) Also

seem to go through similar stages but faster than the UK did

• It helps explain what happened and why in a particular sequence

Weaknesses

• Not very relevant to non industrialised countries• Model assumes stage 2 followed from industrialisation

(For many this was not the case)• The factors that caused falls in DR were often imported

from Europe• Assumes stage 3 follows several decades after stage 2

and that DR fell as a consequence of changes brought about by changes in BR

• Often the onset of stage 3 held back by attitudes to family size, birth control, status, religion

Weaknesses

• Some Govt’s sped up the difference between stage 2 and 3 by introducing one child policies (China)

• Original model only contained 4 stages now 5 to show where DR is exceeding BR (Ageing pop’n)

• DR risen rapidly due to diseases e.g. Africa and Aids – does not help predict this.

DTM and Population Pyramids

Population Pyramids

• These are good for showing the structure of a country’s pop’n

Population Pyramids can show:

• The results of Birth minus deaths in a specific age group

• The effects of migration• The effects of war, famine or disease• An indication of life expectancy

Activity

• Review the following pyramids and see how well you can interpret them

• Think about:• What type of country they are from, where

they are in terms of the DTM and possible reasons for their shape

General Shapes

Age Structures and Problems

• Ageing population• Young population• Low Life expectancy population

• What problems can you foresee with these kind of populations?

Learning Objectives

To learn the concepts behind the DTM Draw, label and interpret pop’n pyramids How population pyramids can be used to

predict pop’n change How various pop’n structures can cause

issues for countries concerned