Demographic Trends and Prospects

Presented by:

Eduard Bos

Health, Nutrition, and Population

The World Bank

John Bongaarts, Population Council, contributed slides

Demographic Trends and Prospects

1) Past trends in population size

2) Projections

3) Determinants of population change: fertility, mortality, and migration

4) Impact of AIDS epidemic

5) Changing age structures

6) Population policy options

World Population Size: Past Estimates and Projections

0

2

4

6

8

10

12

14

1750 1800 1850 1900 1950 2000 2050 2100

Year

Bill

ions World Total

Developing

Developed

World Population Growth by Decade

0

0.5

1

1.5

2

2.5

Per

cent

per

yea

r

0

200

400

600

800

1000

Millions

Source: United Nations 2001, World Bank 2001

Growth rateAbsolutegrowth

1900 1950 2000 2050 2100

China 1,262 1,505 19%

India 1,016 1,561 54%

Indonesia 210 320 52%

Brazil 170 245 44%

Pakistan 138 292 112%

Bangladesh 130 230 77%

Nigeria 127 261 106%

2000 2050 2000-2050

Population size (millions) IncreaseCountry

Projections of Population SizeSelected Countries:2000-2050

Russia 146 114 -22%

Japan 127 105 -21%

Germany 82 67 -17%

How Reliable are Demographic Projections

• Cohort component methodology: trends in vital rates projected separately

• Baseline data: accurate data determine short-term accuracy

• Assumptions about the future: past trends; no “unusual” events

• Longer term: increasing uncertainty

• Global, regional, country, subnational

The Next Billion

1 Billion Increase in Population,1999-2014

0.000

0.200

0.400

0.600

0.800

1.000 High IncomecountriesEurope andCentral AsiaMiddle East andNo. AfricaLatin Americaand CaribbeanEast Asia andPacif icSub-SaharanAfricaSouth Asia

2) Determinants of population change:

fertility and mortality

The Demographic Transition in theDeveloping World

0

10

20

30

40

50

1850 1900 1950 2000 2050

Birt

hs/D

eath

s pe

r 10

00 p

op

Source: United Nations 1998

Birth Rate

Death Rate

Growth Rate

2001

Total Fertility Rate by Region:Past Estimates and Projections

0

1

2

3

4

5

6

7

1950 1975 2000 2025 2050

Birt

hs p

er w

oman

L.America

AfricaAsia

N.America

Europe

2000

Life Expectancy Trends by Region

30

40

50

60

70

80

90

1925 1950 1975 2000 2025 2050

Ye

ars

N. America

Europe

L. America

Asia

Sub-SaharanAfrica

2001

Why Population Growth in LDCs Continues

Fertility remains above the replacement level

Declining mortality

Population momentum due to a young age structure

Population Projections 2000 - 2050, by Region

-50 0 50 100 150

EAST ASIA

SOUTH ASIA

MIDDLE-EAST

SUB-SAH. AFRICA

LATIN AMERICA

NORTH AMERICA

EUROPE

SOUTH

NORTH

WORLD

% increase 2000-2050

Momentum

Standard projection

3) Impact of AIDS epidemic

Global Estimates of HIV Prevalence

Number infected with HIV 9 36 million

Percent of adults infected 0.3 1.2 %

1990 2000

Percent of Adults Infected with HIV in 1999

0 2 4 6 8 10

Sub-Saharan Africa

South and SE Asia

East Asia

Latin America

Europe

North America

% infected

World average

Population Growth Ratewith and without AIDS

0 1 2 3 4 5

2005-10

2000-05

1995-00

1990-95

2005-10

2000-05

1995-00

1990-95

Pop.growth rate (%/year)

South Africa

Botswana

AIDS impact

Source UN 2000

Birth and Death Rate, with and without AIDS in Botswana

0 1 2 3 4 5

2000-05

1995-00

1990-95

Birth/death rate (% of pop)

Source: UN 1998, World Bank 2001

Death rate Birth rate

Pop. growth rate with AIDS AIDS impact

Birth and Death Rate, with and without AIDS in Sub-Saharan Africa

0 1 2 3 4 5

2000-05

1995-00

1990-95

1985-90

Birth/death rate (% of pop)

Pop. growth rate with AIDS AIDS impact

Demographic impact of AIDS

Trends in Under-Five Mortality RatesDemographic and Health Surveys

50

70

90

110

130

150

170

190

210

1980-85 1985-90 1990-95 1995-99

Zambia

Kenya

Zimbabwe

How does HIV/AIDS affect demographic trends

• Mortality of adults (mostly 20-50) increases death rates

• Mortality of adults reduces number of women of childbearing age: fewer births

• Mortality of children increases death rates, reduces future size of adult population

Mortality indicators much worse Dependency ratios not greatly affected

4) Changing age structure

Population Council

Age Structures

High-Income Countries, 2000

40000 30000 20000 10000 0 10000 20000 30000 40000

0-4

5-9

10-14

15-19

20-24

25-29

30-34

35-39

40-44

45-49

50-54

55-59

60-64

65-69

70-74

75-79

80+

Low-Income Countries, 2000

200000 150000 100000 50000 0 50000 100000 150000 200000

0-4

5-9

10-14

15-19

20-24

25-29

30-34

35-39

40-44

45-49

50-54

55-59

60-64

65-69

70-74

75-79

80+

Population Distribution by Age Developing World

0

10

20

30

40

50

60

70

80

90

100

1950 1975 2000 2025 2050

Year

Per

cent

0-15

15-65

65+

2000

Age Dependency Ratio by Region

0

0.2

0.4

0.6

0.8

1

1950 1975 2000 2025 2050

Year

Rat

io

Source: UN 1996

Developed world

Asia

L. America

Africa

2000

5) Population policy options

1)Unwanted fertility and unmet need for contraception and abortion

Strengthen family planning programs

Improve fertility regulation technology

Causes ofPopulation Growth Policy Options

Total Demand and Unmet Need for Contraception among Married Women

0 20 40 60 80

Latin America

Asia / N. Africa

S.S. Africa

% with demand for contraception

Source Bongaarts 1990

Users Nonusers= Unmet need

Wanted and Unwanted Fertilityby Region, Late 1980s

0 2 4 6 8

S.S. Africa

Latin America

Asia / N. Africa

Births per woman

Source: Bongaarts 1990

Wanted Unwanted

Alternative Projections of the Population Size of the Developing World

0

2

4

6

8

10

12

14

16

1900 1950 2000 2050 2100 2150 2200

Bill

ions

Source: Bongaarts 1991; Bongaarts, Phillips, Mauldin, 1990

No programs

Standard WorldBank projection

Effect of:

Remaining unwantedfertility

Existing programs

No unwantedfertility

2) High desiredFamily size

Emphasize human development

1)Unwanted fertility and unmet need for contraception and abortion

Strengthen family planning programs

Improve fertility regulation technology

Causes ofPopulation Growth Policy Options

Women's Average Desired Family Size

0

1

2

3

4

5

6

7

8

Botsw

ana

Burun

di

Gha

na

Kenya

Libe

ria Mal

i

Ond

o Sta

te

Seneg

al

Togo

Ugand

a

Zimbab

weEgy

pt

Mor

occo

Tunisi

a

Indo

nesia

Sri La

nka

Thaila

nd

Bolivi

a

Brazil

Colom

bia

Domin

. Rep

.

Ecuad

or

El Sal

vado

r

Gua

tem

ala

Mex

ico Peru

Trin. &

Tob

.

Des

ired

fam

ily s

ize

Source: Westoff 1991

Sub-Saharan Africa

N.Africa/Asia Latin America

Socioeconomic Factors Affecting Demand for Births

Level of education

Status of women

Infant Mortality

Decomposition of Projected Population Growthin the Developing World

0

2

4

6

8

10

12

1900 1950 2000 2050 2100 2150 2200

Bill

ions

Source: Bongaarts 1994

Standard WorldBank projection

High desired family sizePopulation momentum

Unwanted fertility

10.2

8.3

7.3

4.5

population growthCauses of

Percent Increase in Population Size:Projections for South Asia 1995-2100

0 50 100 150 200 250 300

Sri Lanka

Pakistan

Nepal

India

Bangladesh

Percent Increase, 1995-2100

Momentum

Source Bongaarts and Amin 1997

Median Age at Marriage by Levelof Female Education

14

16

18

20

22

24A

ge

Source: Demographic and Health Surveys

1) Unwanted fertility and unmet need for contraception and abortion

Strengthen family planning programs

Improve fertility regulation technology

Causes ofPopulation Growth Policy Options

2)High desiredfamily size

Emphasize human development

3)Momentum ofpopulation growth

Delay childbearing