Chp . 2- Population

1. Chp. 2- Population KI 3- Why is Population Increasing at Different Rates in Different Countries?

2. THE Demographic Transition • Demographic Transition- the process of change in a society’s population • Process has beginning, middle, and end—historically countries have not reverted back to a previous stage once they have moved on to the next. • However, a reversal may be occurring in some African countries because of the AIDS epidemic

4. Stage 1: low Growth • For most of the time humans have populated the Earth, we have been in Stage 1 • Consequently for a long time out population remained essentially unchanged • Around 8000 bc our population began to grow • Due to the Agricultural Revolution—humans began domesticating plants and animals and no longer relied on hunting and gathering to sustain life • Stable source of food meant more people could survive • However, remained in stage 1 because food supplies were still unpredictable • Today, every nation has moved to at least stage 2

6. Stage 2: high growth • For around 10,000 years after the Agricultural Revolution, world’s population grew steadily at a modest pace • Around the year 1750, population began to grow 10x’s faster than in the past • Growth increased because several countries moved into stage 2 of demographic transition • Result of the Industrial Revolution—began in England in late 18th Century • Conjunction of major improvements in industrial technology that transformed the process of manufacturing goods and delivering them to the market • Led to unprecedented level of wealth which helped make communities healthier places to live • New machines also increased agricultural production—more food!!

8. Stage 2 ct’d • Countries in Europe and North America entered stage 2 around 1800, most countries in Africa, Asia, and Latin America did not enter stage 2 until around 1950 • World population began to grow by 1.7% per year during second half of 20th century, compared to 0.5% during 19th century • Population grew by 8 million in 1900 • Grew by 80 million in 2000 • Africa, Asia, Latin America moved into stage 2 partly due to Medical Revolution—improvements in medical technology diffused to LDCs and eliminated many of the traditional causes of death in those countries

9. Stage 3: Moderate Growth • Move from stage 2 to 3 when CBR begins to drop sharply • Population still growing because CBR is still higher than CDR, however, the gap narrows • Europe and North American countries generally moved from Stage 2 to 3 in first part of 20th century • Most Asian and Latin American countries moved to stage 3 in recent years, but most African countries remain in stage 2 • The CDR drops in stage 2 because of new technologies, CBR drops in stage 3 because of change in social customs • People begin having fewer children—partly because there is a decline in infant mortality

10. Stage 3 Ct’d • Economic changes also affect shift to stage 3 • People in stage 3 are more likely to live in cities • Farmers may consider large families an asset because children can work • Children living in cities are prohibited from working certain jobs and urban homes are relatively smaller than rural homes

11. Stage 4: Low Growth • A country reaches stage 4 when CBR equals CDR and NIR approaches 0 • Called Zero Population Growth (ZPG) • Countries in Stage 4 can be identified by map of total fertility rate—most European Countries have reached stage 4 and United States reached it around 2000 when the total fertility rate began to hover around ZPG • Social customs explain the movement from stage 3 to 4 • Often times, women begin to enter the labor force • Lifestyle changes also encourage smaller families—wider variety of birth controls, people traveling more, etc.

12. Stage 4 Ct’d • Some Eastern European countries like Russia have negative NIRs—caused by former communist rule • Higher death rates from poor pollution controls and lower birth rates from strict family planning and pessimistic view of the world • Shifting back to mirror Western Europe • Read Figure 2-17 in book (pg. 59)

13. Population Pyramids • A country’s stage of demographic transition gives it a distinctive population structure • Population influenced in two principal ways—percentage in each age group, gender distribution • Shape of pyramid usually determined by the CBR

14. Age Distribution • Dependency Ratio- the number of people who are too young or too old to work, compared to the number of people in their productive years • 0-14 and 65+ are classified as dependents • Nearly ½ people living in stage 2 countries are dependents compared to only 1/3 of people in stage 4 countries • Young dependents much more common than elderly ones (10:1) in stage 2 countries • 40% of people are under 15 in sub-Saharan Africa • As countries pass through demographic transition model, number of elderly people increases

16. Sex Ratio • The number of males per hundred females in the population • In general more males are born, but death rates for males are also higher • 93:100 in Europe, 97:100 in North America • LDCs 103:100, more young people, higher infant mortality rates • In U.S. for 15 and under, 105:100 • Women begin to outnumber men around age 40, and comprise 58% of population over age 65 • See figure 2-19 on page 61 • Explain population pyramids of Unalaska, AK; Lawrence, KS

17. Cape Verde: Stage 2 (pg. 61) Chile: Stage 3 (pg. 63) Denmark: Stage 4 (pg. 64)

18. Cape Verde: Stage 2

19. Chile: Stage 3

20. Denmark: Stage 4

21. Read “Global Forces, Local Impacts: Japan’s Population Decline” on page 65

22. Demographic Transition Review • No countries in stage 1, most in 2 or 3, few in 4 • Characterized by 2 breaks—sudden drop in death rate (stage 2), has been accomplished everywhere and comes from technological innovations • Sudden drop in birth rate (stage 4), yet to be achieved by most countries and comes from changing social customs