3.1.4 Demographic Transition

Demographic Transition2.5

2.0

1.5

1.0

0.5

0.01950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050

0

2

4

6

8

10

Gro

wth

rat

e (p

erce

nt)

Po

pu

lation

in b

illion

s

Year

Less developed countries

More developed countries

Why has the world’s population grown at such

different rates throughout history?

Natural increase = births – deathsNet migration = immigrants – emigrants

• Births• Deaths • Migration

What affects birth rates?

Fertility RatesReplacement level fertility = # of

children a couple needs to produce to replace themselves

Total fertility rate = estimate of the average # of children a woman will produce during her childbearing years (15-49)

Births per woman

< 2

2-2.9

3-3.9

4-4.9

5+

NoData

Fertility Rates

What affects fertility rates?• Importance of children to labor force

• Urbanization• Cost of raising and educating children• Education and employment options for

women• Average age of marriage• Availability of pension plans• Availability of legal abortions• Availability of birth control• Religious beliefs, traditions and culture

What affects death rates?

• Higher food supplies• Better nutrition• Improved medical and health

technology• Improved sanitation• Safer water supplies

Indicators of overall health

Growth = natural increase – net migration

•Life expectancy•Infant mortality **

Infant deathsper 1,000 live births

<10<10-35<36-70<71-100<100+Data notavailable

Population(2002)

Populationprojected

(2025)

Infantmortality

rate

Lifeexpectancy

Fertilityrate (TFR)

%Populationunder

age 15

% Populationover

age 65

Per capitaGNI PPP

(2000)

288 million174 million

130 million

346 million219 million

205 million

6.833

75

77 years

69 years52 years

2.12.2

5.8

21%33%

44%

13%5%

3%

$34,100$7,300

$800

United States (highly developed)

Brazil (moderately developed)

Nigeria (less developed)

© 2004 Brooks/Cole – Thomson Learning

Developed Countries

50

40

30

20

10

01775 1800 1850 1900 1950 2000 2050

Rat

e p

er 1

,000

peo

ple

Year

Rate ofnatural increase

Crudebirth rate

Crudedeath rate

Rate of natural increase = crude birth rate – crude death rate

© 2004 B

roo

ks/Co

le – Th

om

son

Learn

ing

Developing Countries

50

40

30

20

10

01775 1800 1850 1900 1950 2000 2050

Rat

e p

er 1

,000

peo

ple

Crudebirth rate

Rate ofnaturalincrease

Crudedeath rate

Year

© 2004 B

roo

ks/Co

le – Th

om

son

Learn

ing

How can economic development help reduce

birth rates?

• Demographers have developed a hypothesis known as the DEMOGRAPHIC TRANSITION.

• It states that as countries become industrialized, first death rates go down and then their birth rates decline.

4 stages of Demographic Transition:

1. Pre-industrial: birth rate and death rate are both high = little growth.

2. Transitional: death rate falls due to improved living and birth rates stay high = rapid growth.

3. Industrial: fertility falls and closes gap between birth and death rates = low growth.

Low

High

Rel

ati

ve

po

pu

lati

on

siz

e

Bir

th r

ate

an

d d

eath

rat

e(n

um

ber

per

1,0

00 p

er

yea

r)

80

70

60

50

40

30

20

10

0

Stage 1Preindustrial

Stage 2Transitional

Stage 3Industrial

Stage 4Postindustrial

Lowgrowth rate

Increasing growth rate

Very highgrowth rate

Decreasinggrowth rate

Lowgrowth rate

Zerogrowth rate

Negativegrowth

rate

Birth rate

Total population

Death rate

Time

4. Post-industrial: birth rate falls below death rate = zero growth.