Why is Population Increasing at Different Rates in Different Countries?

Key Issue #3

Demographic Transition

• Demographic Transition: change in a society’s population; because of diverse local cultural and economic conditions, demographic transition diffuses to individual countries at different rates and produces local variations in natural increase, fertility and mortality– Process of several stages and every country is one

of them; beginning, middle, and end• Barring a catastrophe it is irreversible

The Demographic Transition

Fig. 2-13: The demographic transition consists of four stages, which move from high birth and death rates, to declines first in death rates then in birth rates, and finally to a stage of low birth and death rates. Population growth is most rapid in the second stage.

Stage1

• Stage 1: Low Growth– Lasted several hundred thousand years– Crude Birth and death rates varied considerably

form one year to the next and from one region to another; over long periods of time they were comparable at high levels

– NIR was essentially zero– Earth’s population unchanged at somewhere

around half a million

Stage 1

– Hunter and gathers– Food easily obtained , population increased• Population decreased when food was scarce

– 8,000 B.C. population grew by several thousand per year

– 8000 B.C. to 1750 A.D. population increased from 5 million to 800 million

– Caused by agricultural revolution: domestication of plants and animals and no longer relied on hunting and gathering

8000 B.C to 1750 A.D.

Stage 1

– Created large and more stable food sources; people survived longer

– Remained in stage 1 of demographic transition model because food supplies were still unpredictable

– Farmers prospered in certain regions with abundant harvests and population grew

– Unfavorable climates resulted in low food production, CDR would soar

– War and disease took its effects as well in stage 1

Stage 2

• Stage 2: High Growth– For 10,000 years world grew at a moderate pace– After 1750 grew ten times faster– Occurred in late 18 and 19 centuries because

several countries moved into stage 2– CDR plummets(falls because of new technologies),

CBR remains same as stage 1, difference in CBR and CDR is high, NIR is high, population grows rapidly

Stage 2– 2 PARTS:

• First Part: period of acceleration• Second Part: growth rate slows, gap between birth and

death is high– Countries enter stage because of Industrial Revolution:

began in England in 18th Century and spread to the European Continent and North America during the 19th century• Major improvements in technology that transformed how

goods were made and the delivering of those to the market; steam engine, mass production, powered transportation

Stage 2

– Result was unprecedented wealth , some of it made communities better places to live

– Wealth improved farming and factory techniques and improved sanitation and hygiene• Sewer systems installed, food and water supplies were

protected against containments• People healthier and lived longer• Europe and North America diffused to stage 2 in around

1800; Africa, Asia and Latin America diffused around the 1950s

Stage 2– World population grew by 1.7% per year during the

second half of 20th century compared 0.5% per year during the nineteenth century

– Medical revolution( improved medical technology) that was started in North America and Europe allowed for countries of Africa, Asia, and Latin America to move into stage2 200 years later than Europe and North America• Eliminated many of the diseases that caused deaths in LDC’s• Immunizations to small pox and other disease were developed• Penicillin, vaccines and insecticides effectively and inexpensively

controlled infectious diseases like malaria and tuberculosis

Stage 3

• Stage 3:Moderate Growth– Moves from 2 to 3 when CBR begins to drop sharply– CDR continues to fall in stage 3 but at a much

slower rate than in 2– Population still grows because CBR is still higher

than CDR– Rate of natural increase is more modest in

countries in stage 3 than in 2 because gap between CBR and CDR is narrows

Stage 3

– European Countries and North America moved into stage 3 during first half of 20th century• Asia and Latin America, more recent years• Much of Africa still in stage 2

– CBR changes because of new or different social customs (drops) • Fewer children• Economic changes caused fewer offspring: live cities

instead of farms• Urban homes are smaller

Stage 4

• Stage 4: Low Growth– CBR declines to the point of where it equals the CDR and NIR

approaches zero– Zero Population Growth (ZPG)

• May occur when CBR is still slightly higher than the CDR, some females die before reaching childbearing years and the number of females in childbearing years can vary

• To make up for differences, define ZPG as the TFR that results in a lack of change in the total population over a long term

• TFR of 2.1% results in ZPG– Most European countries have reached state 4– United States reached this stage around 2000

Stage 4– Social customs help explain stage 4

• Women in the labor force• Need child care because both parents work outside of home- before

employment and child rearing took place in the home• Wide range of birth-control• Increase income and leisure time, participate in activities and

entertainment not suitable for children• Russia has negative NIR more deaths than births• Eastern Europe's high death rates and low birth rates are a legacy of

Communist rule• Inadequate pollution control high death rates• Strong family planning lower birth rates• Deep pessimism about having children in a uncertain world

Conclusion

• A country that has passed through all four stages of the model has in some ways completed a cycle- little or no increase in stage 1, to little or no natural increase in stage 4

• Two crucial demographic differences1. CBR and CDRs are high 35 to 40 per 1,000 at the

beginning stage and at the end the rates are very low 10 per 1,000

2. Total Population of the country is much higher in stage 4 than in stage 1