Beyond Population: Everybody
Counts in Development Joel E. Cohen
Rockefeller & Columbia Universities
Center for Global Development, Washington, DC, 2008-09-23
2008-09-23 Joel E. Cohen 2
Population interacts with
economics, environment & culture.
population
culture
economy environment
2008-09-23 Joel E. Cohen 3
2008 world rich poor
population (billion) 6.7 1.2 5.5GNP PPP/person $9,600 $31,200 $4,760% with <$2 / day 40% 0% 48%% increase/year 1.2% 0.2% 1.5%%15-59 HIV/AIDS 0.8% 0.5% 1.0%
infant mortality rate 0.049 0.006 0.054children/woman 2.6 1.6 2.8life expectancy (y) 68 77 67% urban 49% 74% 44%people/km2 49 27 66
2008-09-23 Joel E. Cohen 4
Less developed regions have a bigger,
younger population, 2005.Less developed regions,
5.3 billion
More developed regions,
1.2 billion
300 100 100 300300 200 100 0 100 200 300
Male Female Male Female
Age
Source: United Nations, World Population Prospects: The 2002 Revision (medium scenario), 2003.
80+ 75-79 70-74 65-69 60-64 55-59 50-54 45-49 40-44 35-39 30-34 25-29 20-24 15-19 10-14
5-90-4
2008-09-23 Joel E. Cohen 5
Future population trends to 2050
economy environment
population
culture
2008-09-23 Joel E. Cohen 6
Population from now to 2050
Bigger: 2-4 billion more people by 2050,
mostly in poor countries.
Slower: population growth could end,
depending on choices now.
Older: people 60+ years will outnumber
children 0-4 years.
More urban: added people will be in
cities of poor countries. Rural population
will peak at 3 billion & decline.
2008-09-23 Joel E. Cohen 7
1. Bigger (& different)
population in 2050:
2-4 billion more people,
mainly in poor countries.
2008-09-23 Joel E. Cohen 8
0
2
4
6
8
10
12
1950 1970 1990 2010 2030 2050
year
po
pu
lati
on
(b
illio
n)
World population in 2050 depends
on what we do from now to then.11.9 const.
10.8 high
9.2 med.
7.8 low
billion.
UN, World Population
Prospects: 2006 Revision
One child difference per
woman means ~3 billion
more or fewer people by
2050.
Almost all increase
will be in cities of
developing countries.
2008-09-23 Joel E. Cohen 9
Women who complete secondary school
average at least 1.5 fewer children than those
who complete primary, with cultural differences.Murphy & Carr, Pop Ref Bureau 2007
Demographic & Health Surveys data
< 1
o
1o
com
pl.
2o
co
mp
lete
d
2008-09-23 Joel E. Cohen 10
Demography 2000-2050 simplified
Year 2000: 6.1 billion people
Year 2050: 9.2 billion people
Rural 3 billion Urban 3 billion
Rural 3 billion Urban 6 billion
2008-09-23 Joel E. Cohen 11
medium & low projections, UN 2004
0
400
800
1200
1600
2000
1950 1970 1990 2010 2030 2050
year
popula
tion (m
illions)
USA
Europe
Africa
China
India
Chart: Joel E. Cohen 2007
past future
India’s population size will outgrow China’s.
Africa’s will outgrow India’s & China’s.
Chart: Joel E. Cohen, 2007 Medium & low projections, UN 2004
2008-09-23 Joel E. Cohen 12
Enough food for 3 billion more?
World grows ~1.9 billion tons of cereal
grains/year, enough to feed ~10 billion
people a vegetarian diet.
About 37-40% of grain is fed to domestic
animals to grow meat for those who
can afford it. Brown 2004 Outgrowing the Earth
Billions are chronically malnourished.
¾ billion are chronically undernourished.
2008-09-23 Joel E. Cohen 13
Rising food prices hurt the poor more.
2008-09-23 Joel E. Cohen 14
2. Slower: population growth could end,
depending on choices now, from
lower fertility or higher mortality.
2008-09-23 Joel E. Cohen 15
2008-09-23 Joel E. Cohen 16
Total fertility rate
0
1
2
3
4
5
6
7
8
1950 1970 1990 2010 2030 2050
year
childre
n /
wom
an
Least
Less
More
World
USA
United Nations Population Division, World
Population Prospects: 2006 Revision
“less developed” excludes
“least developed”
2008-09-23 Joel E. Cohen 17
Total fertility in north Africa
0
1
2
3
4
5
6
7
8
1950 1960 1970 1980 1990 2000
year
ch
ild
ren
pe
r w
om
an
Morocco
Algeria
Tunisia
Libya
Egypt
United Nations Population Division, World
Population Prospects: 2006 Revision
2008-09-23 Joel E. Cohen 18
Total fertility in the Middle East
0
1
2
3
4
5
6
7
8
9
10
1950 1960 1970 1980 1990 2000
year
ch
ild
ren
pe
r w
om
an
Turkey
Lebanon
Jordan
Saudi Arabia
Yemen
United Nations Population Division, World
Population Prospects: 2006 Revision
2008-09-23 Joel E. Cohen 19
Total fertility in western Asia
0
1
2
3
4
5
6
7
8
9
1950 1960 1970 1980 1990 2000
year
ch
ild
ren
pe
r w
om
an
Syria
Iraq
Iran
Afghanistan
Pakistan
United Nations Population Division, World
Population Prospects: 2006 Revision
2008-09-23 Joel E. Cohen 20
Slower growth, slow decline
Current population growth is ~78 million / year.
“Developed” countries absorb 5%, developing countries 95%.
By 2050, developed countries will decrease by 1 million persons / year, developing world will add 35 million / year.United Nations Population Division 2005 World Population Prospects: The 2004
Revision, medium variant
2008-09-23 Joel E. Cohen 21
Lower fertility brings smaller families.
People will have fewer siblings, cousins, aunts, uncles.
Reproduction, child-rearing will occupy smaller portion of adult life.
Average number of people per household will decline (unless patterns of cohabitation change), so numbers of households will rise faster than numbers of people.
2008-09-23 Joel E. Cohen 22
3. Older:numbers & fraction of older
people will increase
everywhere, first in rich
countries, then in poor.
2008-09-23 Joel E. Cohen 23
From now on, the world will have
fewer young than old people.
2008-09-23 24
0
5
10
15
20
25
1950 1970 1990 2010 2030 2050% W
orld
Po
pu
latio
n
0 - 4 years
60+ years
People aged 60+ outnumber children aged 0 - 4.
Graph by Joel E. Cohen from
United Nations Population Division estimates and projections (medium variant)
Joel E. Cohen
2008-09-23 Joel E. Cohen 25
Child dependency 0-15 / 15-64
0
20
40
60
80
100
1950 1970 1990 2010 2030 2050
year
ratio
Least
Less
More
World
USA
United Nations Population Division, World
Population Prospects: 2006 Revision
“less developed” excludes
“least developed”
2008-09-23 Joel E. Cohen 26
Elderly dependency 65+ / 15-64
0
10
20
30
40
50
1950 1970 1990 2010 2030 2050
year
ratio
Least
Less
More
World
USA
United Nations Population Division, World
Population Prospects: 2006 Revision
“less developed” excludes
“least developed”
2008-09-23 Joel E. Cohen 27
A tsunami of population
ageing is on the way.
The number of people 60+ will
nearly triple by 2050.
The number of people 80+ will
more than quadruple by 2050.
2008-09-23 Joel E. Cohen 28
Median age will rise everywhere.
2000 2050
world median age (years) 26.7 38.1
more developed regions 37.4 45.7
less developed regions 24.1 36.9
UN Population Division, World Population Prospects 2006 Revision
Relative increase of elderly is most rapid
in some less developed countries.
Greatest numbers of elderly are in more
developed countries.
2008-09-23 Joel E. Cohen 29
Ageing results from 2 successes:
Lower fertility
Longer life
Fall in fertility contributes more to population
aging than increasing length of life.
If birth rates and death rates remain low,
population aging is irreversible.
2008-09-23 Joel E. Cohen 30
Life expectancy rises with income
per person, up to a point.
0
10
20
30
40
50
60
70
80
90
$0 $20,000 $40,000 $60,000
GNI PPP per person US$
life e
xpecta
ncy
Luxembourg
BotswanaSwaziland
PRB 2007 estimates
2008-09-23 Joel E. Cohen 31
A given
income buys
more life as
time passes.
Increasing
knowledge?
Better public
health
measures?
World Bank, World
Development Report 1993
2008-09-23 Joel E. Cohen 32
Life expectancy will increase.(One hopes.)
40
45
50
55
60
65
70
75
80
85
901950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
2015
2020
2025
2030
2035
2040
2045
year
life e
xpecta
ncy a
t birth
(both
sexes)
More developed regionsJapan
Russia
World
Less developed regions
United Nations Population Division
2008-09-23 33
0
5
10
15
20
25
30
'83 '84 '85 '86 '87 '88 '89 '90 '91 '92 '93 '94 '95 '96 '97 '98 '99 '00 '01 '02 '03 '04 '05
Year
Age-Adjusted
Rate
NHIS(70+)
NLTCS(65+)
Sources: NLTCS, Manton, Gu, & Lamb (2006); NHIS, Schoeni,
Freedman, Martin (2006); graph from Robert Schoeni
USA elderly disability rates fell 1.5%
per year in last 25 years.
Joel E. Cohen
2008-09-23 Joel E. Cohen 34
Figure 1. Number of disabled Japanese if disability prevalence had not improved
5.8
6.9
5.5
5.5
4.7
5.3
6.0
0.0
1.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
'93 '94 '95 '96 '97 '98 '99 '00 '01 '02
Year
Millions of
disabled aged
65 and older
Actual
If disability rate
had not changed since 1993
Total population aged 65 and older in each year (in millions)
16.9 19.0 21.2 23.6
Source: As for Table 1.
Japan would have 1.1 million more disabled people
65+ in 2002 if disability prevalence had not fallen
since 1993.
Sources: NLTCS, Manton, Gu, & Lamb (2006); NHIS, Schoeni,
Freedman, Martin (2006); graph from Robert Schoeni
2008-09-23 Joel E. Cohen 35
Top 15 people-killers in 2002,by disease or injury
1. Ischaemic heart
disease
2. Cerebrovascular
disease
3. Lower respiratory
infections
4. HIV/AIDS
5. COPD
6. Perinatal conditions
7. Diarrhoeal diseases
8. Tuberculosis
9. Trachea, bronchus,
lung cancers
10. Road traffic accidents
11. Diabetes mellitus
12. Malaria
13. Hypertensive heart
disease
14. Self-inflicted injuries
15. Stomach cancer
Mathers & Loncar PLOS Medicine 2006
2008-09-23 Joel E. Cohen 36
Tobacco is responsible for about
1 death in 10.
million deaths / year
tobacco 6
HIV / AIDS 3
tuberculosis 2
malaria 1
Mathers & Loncar PLOS 2006; The Global Fund to Fight AIDS, Tuberculosis and Malaria
2008-09-23 Joel E. Cohen 37
“Tobacco … world’s leading
preventable cause of death”“The consumption of cigarettes and other
tobacco products and exposure to tobacco smoke are the world’s leading preventable cause of death, responsible for about 5 million deaths in 2003, mostly in poor countries and poor populations. The toll will double in 20 years unless known and effective interventions are urgently and widely adopted.” World Health Report 2003: Shaping the Future (WHO).
2008-09-23 Joel E. Cohen 38
Tobacco: poor people smoke,
poorest smoke most
Smoking rates have declined in high-income
countries.
Smoking rates have increased sharply in
many low-income & middle-income
countries.
Smoking rates are untouched by public
health measures in poorest nations.Feldman & Bayer, eds. Unfiltered: Conflicts over
Tobacco Policy and Public Health. 2004
2008-09-23 Joel E. Cohen 39
4. More
urban: virtually all
population
growth will be in
cities of poor
countries.
2008-09-23 Joel E. Cohen 40
People are concentrated in cities.
Half of all people (more than 3 billion) live in cities
on less than 3% of censused land area
> 500 people/km2,
> 1 person/(45m x 45m).
Least densely populated half of Earth’s censused
land area has less than 2% of people,
< 10 people/km2.
2008-09-23 Joel E. Cohen 41
Most urban people live in small cities.
Approximately 51% of all urban dwellers
in the world in 2005 lived in cities with
fewer than 500,000 people.
United Nations Population Division
World Urbanization Prospects: The 2005 Revision
2008-09-23 Joel E. Cohen 42
Urban populations, 2000
Asia’s urban population exceeded
that of Africa, Europe, Latin America
and Caribbean combined.
Africa’s urban population
exceeded that of North America and
Oceania combined.
2008-09-23 Joel E. Cohen 43
urban
From 2007- 2008 on, world will have
more urban people than rural.
UN, World Urbanization Prospects 2003
rural
rural
2008-09-23 Joel E. Cohen 44
Urban population will grow faster
in less developed regions.
UN, World Urbanization Prospects 2003
Less developed, rural
Less developed, urban
More developed, urban
More developed, rural
2008-09-23 Joel E. Cohen 45
Total fertility rates decline
from rural to urban areas.
Montg
om
ery
et al. 2
003
2008-09-23 Joel E. Cohen 46
Modern contraceptive use increases
from rural to urban areas.
Montg
om
ery
et al. 2
003
2008-09-23 Joel E. Cohen 47
Unmet need for contraception is
greatest in rural & small urban areas.
Montg
om
ery
et al. 2
003
2008-09-23 Joel E. Cohen 48
Cities will face unprecedented
confluence of rapid increase
in total numbers of people and
numbers of elderly people.
2008-09-23 Joel E. Cohen 49
Cities old & new need to be
designed to accommodate
increasing numbers of the elderly.
Home, work, shopping
should be nearby.
2008-09-23 Joel E. Cohen 50
Cities have environmental impacts.
Cities located on coasts & at river mouths affect wetlands & coastal & offshore fisheries.
Many cities (~3% of land) are located on prime agricultural land (~10% of land). If urban area doubles with doubled population, food production could hurt.
2008-09-23 Joel E. Cohen 51Michiko Shimoda,
Rice field, Fuji City 2005
2008-09-23 Joel E. Cohen 52Michiko Shimoda,
Fuji City 2005
20 “urban agglomerations” had
more than 10 million people in 2005.
On coast or coastal river (15)Tokyo
New York-Newark
Mumbai
Shanghai
Kolkata
Buenos Aires
Dhaka
Jakarta
Los Angeles-Long Beach-Santa Ana
Karachi
Rio de Janeiro
Osaka-Kobe
Al-Qahirah (Cairo)
Lagos
Manila
Inland (5)Ciudad de México
São Paulo
Delhi
Beijing
Moskva
2008-09-23 53Joel E. Cohen
2008-09-23 Joel E. Cohen 54
Sea Level +1M
New York City
Long Beach
Atlantic City
Wildwood
Montauk
New Haven
Weiss and Overpeck, University of Arizona
from Sassen & Schroeder
2008-09-23 Joel E. Cohen 55
Weiss & Overpeck
University of Arizona
from Sassen & Schroeder
2008-09-23 Joel E. Cohen 56
Population interacts with
economics, environment & culture.
population
culture
economy environment
57
Further informationCohen, How Many People Can the Earth
Support? (W. W. Norton, NY, 1995)
Cohen, Human population: the next half
century. Science 302:1172-1175, 14 Nov.
2003
Cohen, Human population grows up.
Scientific American special issue
“Crossroads for Planet Earth” September
2005.
Cohen, Bloom, Malin, Educating All Children:
A Global Agenda (MIT Press, 2007)2008-09-23 Joel E. Cohen