5 Demographic Transition model
Transcript of 5 Demographic Transition model
Definitions
• Infant Mortality: It is defined as the proportion of children who die before they reach the age of one year
• Life Expectancy: It is the number of years that a child born in a particular country in a certain year can expect to live
Demographic Transition Model
Population increase= Natural increase + rate of net migration
These changes are analyze in a Demographic Transition Model
There are 4 stages in the model
• The Demographic Transition Model attempts to show how population changes as a country develops.
• The model is divided into four stages.
• The Demographic Transition Model does not take into account migration.
The Four Stages
Stage 1• Birth rate is high • Death rate is high • Low natural increase - low total population
Factors • Children provide security & Labor• Religious beliefs encourages large families • poor or inadequate medical care & sanitation
Give Examples?
Stage 1: Pyramid Structure
•Due to high birth rates, the pyramid shape would have a wide base; •Due to high death rates, the pyramid would be very short in height; concave shape indicates low life expectancy.
The Four Stages
Stage 2 • Birth rate is high – • death rate is falling –• high natural increase (population growth)
Factors• Birth rates high because of cultural factors• Advances in medical care and sanitation
Give Examples?
Stage 2 : Pyramid Structure
• As death rates fall, the population explosion begins;• The height of the pyramid grows to reflect the prevention of more
deaths; shape becomes less concave as life expectancy increases;• The width of the base remains large due to the ongoing high birth
rates
The Four Stages
Stage 3• Falling birth rate • Low death rate• High natural increase
(population growth)
• The “gap” closes, population increase slows down
Factors• Realization-large families are unnecessary• Family planning becomes available • Parents favor material things, not large families, • Woman become more involved in the workforce
Give Examples?
Stage 3: Pyramid Structure
• As birth rates begin to be addressed, the base begins to stabilize and eventually narrow;
• Death rates are low and stabilized, meaning that the pyramid continues to grow higher.
The Four Stages
Stage 4• Birth rate is low• Death rate is low • low natural increase - high total population • Small “gap” like in stage 1
(Population may be declining)
Give Examples?
Stage 4: Pyramid Structure
• Birth rates and death rates are low; as fertility continues to decline, an AGING SOCIETY emerges.
• Pyramid seems to “invert”
MEDC vs. LEDC
Note the quick transition to Phase 3 from the explosion of Phase 2
Note the longer time period as LEDC’s are “trapped” in Phase 2
Criticism of DTM• The model is an over-generalization of the industrialized
European experience• Industrialization is difficult to achieve for LEDC’s in a trading
system that protects the industries of MEDC’s;
• Model assumes all countries proceed from stage 1-4; • It ignores variables and exceptions (ie. War, political turmoil)
• The model assumes that reductions in fertility are a function of increased wealth and industrialization–
• Other factors such as the status of women and other social development are ignored.