Population 2- The DTM Flashcards
The Demographic Transition Model
Describes how the population of a country changes over time
Gives changes in birth rates and death rates
Stage 1
High fluctuating- high BR & high DR
E.g. Remote tribes
Stage 2
Early expanding- high BR & falling DR
E.g. Sub-Saharan Africa
Stage 3
Late expanding- low DR & falling BR
E.g. Mexico
Stage 4
Low fluctuating- low BR & low DR
E.g. UK
Stage 5
Decline- falling BR & low DR
E.g. Germany
Reasons for high birth rates
High IMR, need for labour, religion & lack of birth control
Reasons for low BR
Lower IMR, industrialisation, family planning & contraception, cost of children
Reasons for high death rate
Lack of food security, poor hygiene, diseases, poor healthcare
Reasons for low death rates
Improvements in food production, improved sanitation & transport, improved healthcare
Advantages of the DTM
Universal, comparison, easy to understand (clear), flexible timescales, predict, evidence of examples
Disadvantages of the DTM
Doesn’t account for migration, Eurocentric, doesn’t include the role of government (aid/policies), distorted by HIV/AIDS, slowed by religion
Population pyramids
Shows the results of births minus deaths and migration, effects of events like war and disease, indicates the life expectancy
Dependency ratio
Shows the relationship between the economically active and the economically inactive (dependant)
Juvenility index
Shows the proportion of younger people in the population
Old-Age Index
Shows the proportion of elderly people in the population
Support ratio
Inverse of the dependency ratio
Stage 1 PP
Wide base (high BR), concave sides (high DR), short pyramid (low life expectancy)
Stage 2 PP
Wide base (BR still high), more triangular (lower DR), slightly taller (higher life expectancy)
Stage 3 PP
Narrower base (falling BR), convex sides (DR falling)
Stage 4 PP
Narrow base (low BR), convex/vertical sides (low DR), taller pyramid (higher life expectancy)
Issues in a Youthful Population
High percentage of young dependants needing: water, food, housing, sanitation, education, healthcare
Leads to squatter settlements, pollution & deforestation
