Demographic Changes
Demographic Transition Model
Transitions In World Population
Calculating Population Change
• Population changes as result of four
variables:
– Births + immigration = increase
– Deaths + emigration = decrease
• (CBR+I)-(CDR+E)= Total population
• This equation better suited to study
population trends rather than specifics
• In what ways might geographers use this
data?
Demographic Transition Model
• Used to determine stages of a country’s growth
• Graphs population, time, birth and death rates
(doesn’t account for migration)
• Used to correlate a country’s progress in
technology and society
P
o
p
Stages/Time
Stage 1: Low Growth
(High Stationary)
• Overall Population is sparse
• High birth-high death= stationary pop
• Lack of major food surplus keeps
population low
• Super long doubling time
• ALL WORLD REGIONS UNTIL 17th C
• Agricultural Revolution: domesticated
plants/animals make for better food
sources and lead to transition
Population graph for the first four million years
Stage 2: High Growth
(Early Expanding)
• CDR decreases rapidly (especially people
under the age of 5)
• CBR remains steady
• Results in natural increase
• Industrial Revolution
– Technology produces and transfers goods
– Industry and farming improve
• Sanitation improvements- examples?
• Medical advancements- examples?
• Bangladesh, Nigeria, Pakistan
Stage 3: Moderate Growth
(Late Expanding)
•
•
•
•
CBR drops
CDR drops but slower than stage 2 decrease
NIR is modest
CBR drops because of new technologies
– People have fewer kids
– Medical advances mean less chance of children dying
– Economic factors: less farming more urban
• How does this correlate?
– Women become better educated
• How does this correlate?
– China, Brazil, Mexico, India
Entering Stage Three
Even though birth rate is falling, population momentum keeps the total
population growing.
Stage 4: Low to No Growth
(Low Stationary)
• CBR=CDR (little to no growth)
• Most European nations in Stage 4
– U.S. moving in this direction
• Social Customs
–
–
–
–
Women working
Employed parents need to plan for day care
Entertainment and leisure activities
EXPLAIN!
US, Sweden, Japan, Britain
Stage 1
Stage 2
Low growth
incr grwth
Stage 3
Stage 4
Birth
Rate
Death
Rate
Total
Popul
ation
decr grwth
low/no
Problems with the Model?
• No "guidelines" for how long it takes a to get
from Stage I to IV. Just describes it
– Western Euro countries took centuries
– Economic Tigers took decades.
• Nations that were populated by emigration
did not go through early stage
• Birth rates have fallen below death rates in
some areas, should there be a stage V?
PROPOSED FIFTH STAGE:
• Negative population growth
• CBR drops to zero-CDR very low-population
is slowly dying out (Children of Men)
• Not enough people in the work force to
support programs for the aged (dependency
ratio very lopsided)
• Social programs overloaded-unrest &
probable chaos
• Innovations stagnant
Prezi