1. Chapter 2: Population
Key Issue 3

2. Key Issue 3
Why is Population Increasing at Different Rates in Different Countries?
The demographic transition
Population Pyramids
Countries in different stages of demographic transition
Demographic transition and world population growth

3. Demographic Transition
Countries experience changes in natural increase, fertility and mortality rate at different times & at different rates
Differences in local culture and economic conditions

4. Demographic Transition
Several stages: beginning, middle & end
Stage 1: Low Growth
Stage 2: High Growth
Stage 3: Moderate Growth
Stage 4: Low Growth

5. Describe each of the 4 stages
Figure: 02-13
Title:
Demographic transition.
Caption:
The demographic transition consists of four stages: stage 1–very high birth and death rates produce virtually no long-term natural increase; stage 2–rapidly declining death rates combined with very high birth rates produce a very high natural increase; stage 3–birth rates rapidly decline, death rates continue to decline, and natural increase rates begin to moderate; and stage 4–very low birth and death rates produce virtually no long-term natural increase, and possibly a decrease.

6. Stage 1: Low Growth Early civilization
High levels of birth & death rates
NIR of zero
People depended on hunting & gathering for food
Access to food varied by year, increasing or decreasing population

7. Stage 1: Low Growth Agricultural Revolution
People domesticated plants & animals
Created a stable source of food
Population began to increase
Unfavorable harvests could still result in low food production
War and disease also affected population growth

8. Stage 1: Low Growth
No country remains in stage 1 today

9. Stage 2: High Growth Due to Agricultural Revolution, population grew
Around 1750, pop. Inc 10x faster
CDR decreased, CBR remains about the same
Margin causes increase in population (NIR)

10. Stage 2: High Growth Industrial Revolution Began in England, 1750
Spread to Europe & North America
Industrial technology (steam engine, mass production, powered transportation)
Led to wealth:
Improved sanitation
Food & water supplies

11. Stage 2: High Growth Africa, Asia, Latin America Medical Revolution
Did not reach stage 2 until 1950s+
Medical Revolution
Eliminated traditional causes of death
Longer & healthier lives
Ex: vaccines, penicillin & insecticides

12. Stage 3: Moderate Growth
Reached when CBR drops sharply
Began in Europe & North America in 1900s
Social customs cause CBR to drop
People CHOOSE to have less children
Improved probability of infant survival
Economic changes:
Large families no longer needed for farms
Families moved to city jobs
Children become more expensive in urban areas

13. Where are the sudden spikes of population?

14. Stage 4: Low Growth CBR is equal to CDR, NIR approaches ZERO
Zero Population Growth (ZPG)
A TFR approx 2.1 produces ZPG
Immigration can affect ZPG, where TFR needs to be even lower

15. TFR of 2.1 or below is needed to reach ZPG. Observations?

16. Stage 4: Low Growth Social Customs changing population
Women entered work force
Shift away from farm jobs
Daycare for young children
Birth control
More wealth  Inc. in leisure time, not suitable for children

17. Stage 4: Low Growth Russia (Eastern Europe) Cause: Communist Rule
Negative NIR, deaths exceed births
Cause: Communist Rule
Indadequate pollution control
Pessimism about having children

18. Demographic Transition
Countries that pass through all four stages have completed a cycle
Stage 1: ZPG to Stage 4: ZPG
Stage 1: high CBR & CDR
Stage 4: low CBR & CDR

19. The Demographic Transition in England
Good Case Study:
accurate records of population (past 1000yrs)
No boundary changes
Not greatly affected by migration

20. Writing Assignment Explain the Demographic Transition
Define each stage
Explain what leads to each transition to next stage
Provide examples

21. Population Pyramids
Stage of Demographic Transition determines what population of a country looks like
Percentage of each age group
Gender distribution

22. Population Pyramids
A bar graph that displays a country’s population by age and gender
Percentage of total population
in 5yr age groups, youngest at
bottom, oldest at top
Percentage of males, females
represented by length of bars

23. Population Pyramids CBR determines shape of pyramid
Stage 2 country: high growth
High CBR, large number of children
Broad base of pyramid (wide at bottom)
Stage 4 country: low growth
Large number of older people
Broad top of pyramid

24. Age Distribution
Dependency ratio: number of people who are too young or too old to work, compared to people in productive years
Dependents are: 0-14 and 65+yrs old
Determine dependency ratio of classroom

25. Age Distribution Stage 2 Stage 4
50% of population are dependents (1:2)
Young dependents outnumber elder dependents 10:1
Stage 4
33% of population are dependents (1:1)
Amt of young dependents = Elder dependents
How will amount and age of dependents impact a society?

26. Age Distribution Sub-Sahara Africa & Stage 2 (high-growth) countries
Large percentage of pop. under age 15
Strains country’s resources
Hospitals, schools, daycare
Job scarcity post high school

27. Age Distribution
Percentage of elders increases as countries move towards Stage 4 of Dem. Trans.
Declining CBRs
Improved medical care
Higher incomes
Europe: 65+ is 16% of population
Sub-Saharan Africa: 65+ is 3% of population

28. Age Distribution United States, Canada, Japan, Europe
More than ¼ of gov’t expenditures go to health care, Social Security & programs for older populations
Stage 3 & 4 countries
Higher population of elderly
Causes higher CDR
What concerns are there with our aging population?

29. Sex Ratio Number of males per hundred females in a population
Slightly more males born than female
Males have higher death rates
Europe & North America 95: 100 (m:f)
Rest of world is 102:100 (m:f)
What could be the reason?

30. Life Expectancy Shrinks for Poor People in the US
Read newspaper article and answer questions

31. Sex Ratio United States Under age 15yrs old, 105:100 (m:f)
Women outnumber men around age 40
Why????
58% of population 65+ are women

32. Sex Ratio LDCs High mortality rate during childbirth
Larger percentage of young people (males outnumber females)
Lower percentage of older people (females are more numerous)

33. Population Pyramids
What could explain these differences in age and gender throughout the United States?

34. Similar Population Pyramids Why???
What do you know about birth rates for African-Americans and Hispanics?

35. What do we know about these locations
What do we know about these locations? How does that help explain the age distribution?

36. Countries in Different Stages of Demographic Transition
Stage 1: low growth: none
Stage 2: high growth: Cape Verde
Stage 3: moderate growth: Chile
Stage 4: low growth: Denmark

37. Cape Verde: Stage 2 12 small islands off the coast of W Africa
Famine kept it in Stage 1 until 1950
Antimalarial campaign moved it to Stage 2

38. Chile: Stage 3 Shifted from rural to urban
Moved from Stage 1 to 2 with medical advancements (smallpox, malaria)
Moved to Stage 3 because of gov’t family planning initiatives, 1966
(prevented abortions for unwanted births)
Reversed family planning policies, 1970
Chileans continue to have large families
Large Catholic population

39. Denmark: Stage 4 Similar to England’s trends in population
Since 1970s, CBR = CDR…ZPG
Population is only increasing from immigration