1. Chapter 5: Population Theories
Unit 2: Human Population

2. The Theory of Demographic Transition
Demographic Transition: Phenomenon of a country’s high birth and death rates changing over time to low death and birth rates

3. The Theory of Demographic Transition
Stage 1: Pre-Transition
Sweden was a great benchmark to monitor demographic transition (Figure 5-1, p. 62)
Birth rate was relatively stable, but death rate fluctuated b/c of wars, famine
Now, Mexico is used b/c it is in a pre- transition stage (Figure 5-2 p. 62)

4. The Theory of Demographic Transition
Decrease of pop. in each age group indicates high birth rates, and high death rates in all age groups (Fig 5-3, p. 62)
Life expectancy in Sweden in 1750 was barely 35 years
Birth and death rates are relatively high in pre-transition stage

5. The Theory of Demographic Transition
Stage 2: Early Transition
All societies in the world are now at least in the early transition stage, with lower death rates (Figures 5-4 & 5-5, p. 63)
The death rate dropped, while birth rate remained high
Developing countries are at this stage

6. The Theory of Demographic Transition
Germ Theory: Theory that some diseases are caused by microscopic organisms
It was not widely accepted but proved to reduce death rates by doctors disinfecting their hands. (Ignaz Semmelweis, Austria)
Infant mortality rates drop increasing family sizes and society’s child dependency load (Fig 5-6, p. 64)

7. The Theory of Demographic Transition
Stage 3: Late Transition
Large families were no longer sustainable, birth rates began declining, while death rates remained low
Early transition has “death control”, while late transition has “birth control” (Fig 5-8 & 5-9, p. 66)
Population explosion still occurs since birth rates are still high but continue to decline as time goes on

8. The Theory of Demographic Transition
Birth control here is how couples decide to have less children
Movement into cities also lead to this “birth control”
Also, women entering the workforce
Birth rates began approaching death rates (Fig 5-10, p. 66)

9. The Theory of Demographic Transition
Stage 4: Post-Transition
Birth and death rates are low and very close to each other (Fig 5-11, p. 67)
High dependency load of seniors (Fig 5- 12, p. 67)
It takes a long time for countries to enter post-transition b/c more people enter child bearing years than leave them
Very new stage of demographic transition, so future pop. trends are all theoretical

10. The Theory of Demographic Transition
Summary
All countries are diff. b/c of their history (Fig 5-13, p. 68)
As a country goes through these stages, they are progressing economical and socially (Fig 5-14, p. 68)
Pyramids show whether pop. is stable or changing (Fig. 5-15, p. 69)

11. Differing Ideas About Population Growth
Optimists focus on adaptation, pessimists look at problems
Optimistic Views
Expressed by religious leaders, and secular leaders interested in economic and militaristic expansion

12. Define: pages 70-73 Optimistic Views Cornucopians
Bogue, Theory of demographic regulation
Pessimistic Views
Malthus
Catton, phantom carrying capacity
Population Projections for the future.