1. The study of the human population
World Demography
The study of the human population

2. Objectives
Describe how size and growth rate of human pop has changed in the past 200 years
Define 4 properties that are used to predict population sizes
Describe 4 stages of demographic transition
Explain why different countries may be at different stages of demographic transition
Make predictions about population trends

3. Populations
The study of human populations has its own term: Demography
Demographers study many factors of a population to predict its future size
One factor is whether the country is developed or developing.

4. Do you recall… Lower average incomes Higher average incomes
Developing Countries
Developed Countries
Lower average incomes
simple/farm-based economies
Rapid population growth
Higher average incomes
Diverse/industrial economies
Slower population growth

5. Forecasting Population Size
There are 4 properties we can use to predict changes to a population

6. 1. Age Structure
Definition: the distribution of ages in a specific population at a certain time.

7. Q: What will happen to Scotland’s population in 20 years?
Will they need more schools? More nursing homes? More room in cemetaries?

8. 2. Survivorship
Definition: the percentage of group members that are likely to survive to a given age.
Type I: Wealthy, developed nations; populations are healthy and many live to old age
Type II: similar death rate at all ages
Type III: poor populations; high infant/children mortality rate

9. 3. Fertility Rate
Definition: The number of babies born each year per 1,000 women

10. What would cause a change in number of babies born?

11. Fertility with replacement level
The Replacement Level is the number of children that must be born to replace their parents.
Which populations are shrinking?
Which populations are still growing?
Trick Question! None will grow!
Trick question – none of the countries are reaching the replacement rate of 2.1 per year!

12. 4. Migration Definition: The movement of individuals between areas.
Immigration: movement coming into an area
Emigration: movement coming out of an area

13. Natural Increase + Migration

14. Factors that change populations

15. Many historic factors have changed populations
Industrial Revolution led to access to
Food
Clean water
Safer work-places
Advancements in medicine

16. Life Expectancy
These historic factors changed our nation’s life expectancy
Life expectancy is the average number of years people are likely to live.

17. The Demographic Transition
An eventual change in population

18. Population Transition
What causes a population to stop growing and start decreasing?

19. Population Transition
Definition: a model that describes how economic and social changes affect population growth rates.
Scientists base this on observations and statistical data of other factors.
Demographic transition happens in 4 stages.

20. Stage 1: Preindustrial Condition
Birth rate – high
Death rate – high
Population size is stable

21. Stage 2: Population explosion
Birth rates – high
Death rates – drop due to social improvements
Population grows very fast

22. Stage 3: Birth Rate Drops
Birth Rate – decreases
Death rate – still low
Population size stabilizes to steady

23. Stage 4: Transition Birth rate – drops below replacement level
Death rate – still low
Population size starts to decrease since not enough children are born to replace the older generations

25. What type of graph is this?