population projections: assumptions first, results second

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Carl Haub [email protected] Senior Visiting Scholar Population Reference Bureau

Population Projections: Assumptions First, Results Second

© 2009 Population Reference Bureau. All rights reserved. www.prb.org

World Population

1900

1.6 Billion


World Population

2000

6.1 Billion


300 200 100 00 100 200 300

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

80-84

85+

Female

Fewer young people in developed countries ensures little population growth or even population decline.

Age

Millions

Male

United Nations Population Division, World Population Prospects: The 2010 Revision (medium variant).


300 200 100 00 100 200 300

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

80-84

85+

Female

Large numbers of young people in developing countries guarantee large population growth. Age

Millions

Male



What’s Required for a Projection?

1. Base population 2. Assumption on the future course of fertility 3. Assumption on the future course of mortality (infant mortality, life expectancy at birth) 4. Assumption on the future course of

immigration/emigration


The Total Fertility Rate (TFR)

The TFR is the average number of children a woman would bear in her lifetime if the birth rate of a particular year were to remain constant.


The Assumption Behind the Assumption

“To achieve such reductions, it is essential that access to family planning expands, particularly in the least developed countries.”

World Population Prospects, The 2010 Revision, Highlights and Advance Tables


And Further to the Point…

“The urgency of realizing the projected reductions of fertility is brought into focus by considering that, if fertility were to remain constant at the levels estimated for 2005-2010, the population of the less developed regions would increase to 9.7 billion in 2050 and to 25.8 billion in 2100 instead of the 8.0 billion and 8.8 billion projected by assuming that fertility declines.”

World Population Prospects, The 2010 Revision, Highlights and Advance Tables


7.0

8.2

6.9

8.0

2010 2025

1982 UN projection 2010 UN projection

United Nations Population Division, World Population Prospects, as Assessed in 1982 (medium variant) and World Population Prospects: The 2010 Revision (medium variant).

World Population for 2010 and 2025 in Two UN Projections

Billions


1.2

1.6

1.0

1.4

0

1

1

2

2

2010 2025

1982 UN projection 2010 UN projection

United Nations Population Division, World Population Prospects, as Assessed in 1982 (medium variant) and World Population Prospects: The 2010 Revision (medium variant).

Population of sub-Saharan Africa for 2010 and 2025 in Two UN Projections

Billions


5.3

2.2

5.6

2.12.5

3.1 3.2

4.0

6.0

2.5

5.6

2.31.9

3.6

2.2

6.4

0

1

2

3

4

5

6

7

BurkinaFaso

India Nigeria Indonesia Brazil Pakistan Bangladesh Burundi

1982 ProspectsCurrent TFR

TFR for 2010 as Projected in 1982 and Likely Current Value Children per woman

United Nations Population Division, World Population Prospects, as Assessed in 1982 (medium variant)


1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

1950-1955

1955-1960

1960-1965

1965-1970

1970-1975

1975-1980

1980-1985

1985-1990

1990-1995

1995-2000

2000-2005

2005-2010

2010-2015

2015-2020

2020-2025

2025-2030

2030-2035

2035-2040

2040-2045

2045-2050

EasternMiddleSouthernWestern

Estimated and Projected TFR for Regions of Africa to 2050


Children per woman


0.0

1.0

2.0

3.0

4.0

5.0

6.0

1995-2000 2000-2005 2005-2010 2010-2015 2015-2020

UN MediumIDBSurveys

TFR Assumptions, Mozambique, Two Projections vs. Surveys

United Nations Population Division, World Population Prospects: The 2010 Revision and U.S. Census Bureau, International Database

Children per woman


0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

1995-2000 2000-2005 2005-2010 2010-2015 2015-2020

UN MediumIDBSurveys

TFR Assumptions, Bangladesh, Two Projections vs. Surveys


Children per woman


0.0

1.0

2.0

3.0

4.0

5.0

6.0

1995-2000 2000-2005 2005-2010 2010-2015 2015-2020

UN MediumIDBSurveys

TFR Assumptions, Rwanda, Two Projections vs. Surveys


Children per woman


0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

1986

1987

1988

1989

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

Children per woman

Demographic and Health Surveys. Note: Gray circles indicate a census estimate

Future fertility decline in sub-Saharan Africa is quite doubtful, based on the results of recent surveys.

Circles indicate survey/census years

Niger

Ghana

Zambia

Nigeria


Children per woman

Demographic and Health Surveys and various surveys in Pakistan.

Slow or little fertility decline is not confined to sub-Saharan Africa.

Circles indicate survey years

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

Pakistan

Indonesia

Jordan Egypt


6

2

11

3

10

1 1

12

1

27

3

1

3

6

221

13

0

6

12

0

6

0

5

10

15

20

25

30

Eastern Africa Middle Africa Southern Africa Western Africa

PillIUDInjectionCondomFemale sterilizationTraditional Methods

United Nations Population Division, World Contraceptive Use, 2011

In Sub-Saharan Africa, Short-acting Methods Predominate

Percent of married women using


5.0

4.4 4.2

3.3

5.6 5.4

2.3

5.0

6.3 6.1

3.7

5.7

4.3

2.4

5.1

6.4

4.8

4.1

6.3

5.4

2.5

0

1

2

3

4

5

6

7

Sierra Leone Burundi Ethiopia Zimbabwe Angola Tanzania Peru

UN MediumIDBSurvey

United Nations Population Division, World Population Prospects: The 2010 Revision and Demographic and Health Surveys and other surveys

Projected TFRs vs. Recent Surveys, ca. 2010

Children per woman


4

24

15

3

16

27

1

10

37

1

9

38

Too low Satisfactory Too high

1976198619962009

Reported Government View on the Level of the Birth Rate, Sub-Saharan Africa, 1976 - 2009

Number of Countries

United Nations Population Division, World Population Policies, 2009


0

1

2

3

4

5

6

7

1800

1810

1820

1830

1840

1850

1860

1870

1880

1890

1900

1910

1920

1930

1940

1950

1960

1970

1980

1990

2000

2006

BangladeshU.S.

Lifetime children per woman

Fertility Decline in Bangladesh and the United States, 1800 - 2006 Two Very Different Histories

Population Reference Bureau, NCHS, DHS surveys


0

1

2

3

4

5

6

7

8

1950-1955 1955-1960 1960-1965 1965-1970 1970-1975 1975-1980 1980-1985 1985-1990 1990-1995 1995-2000 2000-2005 2005-2010

In quite a few developing countries, fertility decline has been rather smooth.

United Nations Population Division; and Demographic and Health Surveys.

Lifetime births per woman

Tunisia

Brazil

Dom. Rep.

Thailand


0

1

2

3

4

5

6

7

8

1950-1955

1955-1960

1960-1965

1965-1970

1970-1975

1975-1980

1980-1985

1985-1990

1990-1995

1995-2000

2000-2005

2005-2010

ThailandMalaysiaTunisiaBrazilDominican Republic

Other Developing Countries with Significant Fertility Decline

Population Reference Bureau, DHS surveys



1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

5.5

6.0

1950-1955

1955-1960

1960-1965

1965-1970

1970-1975

1975-1980

1980-1985

1985-1990

1990-1995

1995-2000

2000-2005

2005-2010

Total Fertility Rate, Sri Lanka, 1950-55 to 2005-2010


Children per woman


2.9 2.9 2.8 2.9 2.9 2.9

3.2 3.12.9 2.9 2.9 2.8

3.3 3.43.2 3.3 3.2

0

1

2

3

1988

1992

1995

2000

2005

2008

1987

1991

1994

1997

2002

-0320

0719

9119

9619

9920

0220

07

Demographic and Health Surveys (DHS)

How Many Children Do Women Say Are “Ideal?”

Egypt Indonesia Jordan

Latest DHS total fertility rate in red 3.0 2.6 3.8


6.8

5.65.1 5.3

6.25.7

5.1 5.1

8.5 8.59.1

0

1

2

3

4

5

6

7

8

9

1988

-8919

95

2000

-0120

0619

9219

96

2001

-0220

0719

9219

9820

06

Demographic and Health Surveys (DHS)

How Many Children Do Women Say Are “Ideal?” – con’t

Uganda Zambia. Niger 6.2 6.2 7.1

Latest DHS total fertility rate in red


6 6 6 6

5

4

3

0

1

2

3

4

5

6

7

Niger 2006 Mozambique2011

Burkina Faso2010

Nigeria 2008 Zambia 2007 Jordan 2009 Pakistan2006-2007

With How Many Living Children Do Half of Women Say That They Wish to Cease Childbearing?

Demographic and Health Surveys.

++ + + +


Fertility Rates in India Are Not Uniform, 2008 Data

2.6

2.0

2.9

3.9 3.8

3.33.0

2.6 2.5 2.5 2.42.2

2.0 2.0 2.0 1.9 1.9 1.9 1.8 1.7 1.7

INDIA

URBAN

RURALBihar

Uttar P

radesh

Rajasth

an

Chhattisgarh

Assam

Haryana

Gujarat

Orissa J&

K

Karnata

ka

Mahara

shtraDelh

i

Punjab

West Ben

gal

Himach

al Prad

esh

Andhra Prad

esh

Kerala

Tamil Nadu

Registrar General of India, Sample Registration System



21.5

15.013.5

7.1

4.1

15.6

6.7 6.24.7

7.1

0.0

5.0

10.0

15.0

20.0

25.0

Zambia Kenya Central Af. Rep. Cote d'Ivoire Uganda

Before surveyAfter survey

UNAIDS and Demographic and Health Surveys (DHS)

Before Nationally-representative Surveys Were Taken, the Prevalence of HIV Was Often Overestimated – but Still High

Percent of adult population, ages 15-49 with HIV

Note: DHS Surveys from 2003 to 2006


Total Fertility Rates, Selected EU 15 Countries and the U.S., 1960 - 2011

1.0

1.5

2.0

2.5

3.0

3.5

4.0

1960 1963 1966 1969 1972 1975 1978 1981 1984 1987 1990 1993 1996 1999 2002 2005 2008 2011

GermanySwedenItalyFranceU.S.A.

Council of Europe, Recent demographic developments in Europe and national statistics websites

Children per woman


5 4 3 2 1 0 1 2 3 4 5

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+

Female

Age

Percent

Male

Source: Federal Statistical Office of Germany, Statistical Yearbook, 2010 (2009 data).

Small numbers of young people in many developed countries have all but guaranteed fewer future births.

Germany, by age and sex


Females

Population of Japan by Age and Sex, 1 December, 2009

Japan Statistics Bureau

Age

Millions

Males


20.5

6.5

9.1

2.1

7.56.5

5.6

0.9 0.9

23.2

19.6

14.1 14.113.1

10.4

8.4

1.7 1.1

Switzerla

nd

Irelan

d

Sweden

Spain

German

yU.K

.

Malaysia

Japan

Jamaic

a

19902010

Population of Foreign Stock, Selected Countries, 1990 and 2010

Percent

United Nations, International Migrant Stock, the 2008 Revision



World Population (in Billions): 1950-2050

0

1

2

3

4

5

6

7

8

9

1950

1955

1960

1965

1970

1975

1980

1985

1990

1995

2000

2005

2010

2015

2020

2025

2030

2035

2040

2045

2050

Developing Countries

Developed Countries

Billions

Virtually all population growth is in the world’s poorest countries.


Thank You

population projections: assumptions first, results second

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