5. Population

8/2/2019 5. Population

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ECON 181

Population.

WARNING: The slides are NOT lecture notes. You still need to read the assigned papers.

Econ 181: Population October 24, 2011 1


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Contents

1 Motivation and definitions 4

1.1 Why population? . . . . . . . . . . . . . . . . . . . . . 5

1.2 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . 6

2 A brief history of human population 9

3 The present demographic situation 11

4 The causes of population growth 25

4.1 Malthus, the Pessimist . . . . . . . . . . . . . . . . . 26

4.2 Modern theories . . . . . . . . . . . . . . . . . . . . . 27

5 Population and development 29



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5.1 Population and accumulation . . . . . . . . . . . . . . 30

5.2 Population and productivity . . . . . . . . . . . . . . . 31

5.3 Population and market failures . . . . . . . . . . . . . 32

6 Population policy 34



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1 Motivation and definitions



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1.1 Why population?

The production function.

What are the predictions of the Solow model?

Economies of scale and the size of the market.

The McNamara-Wolfensohn debate.

Food prices and environmental issues.



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1.2 Definitions

(Crude) Birth rate: births per thousand of population.

(Crude) Death rate: deaths per thousand of population.

Rate of natural increase: is the difference between the birth

rate and the death rate.

Question: Is the natural rate positive or negative?



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Age structures: cohorts.

Infant death rate: deaths in the first year of life perthousand live births.

Life expectancy: number of additional years the average

person of a given age will live if age-specific death rates are

constant.

Most used: life expectancy at birth.

Fertility: propensity to have children.

Age-specific fertility rate: average number of children born

to women in a particular age group.

Total fertility rate: number of children the average women

will have in her lifetime if age-specific fertility rates remain

constant.



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2 A brief history of human population

Pre-agriculture era: low population density, high birth and

death rate. 100 million by the end of this era (12,000 BC).

From settled agriculture to the industrial revolution:agriculture starts, more reliable food supply, lower death rates,

population growth 0.5% a year. 1.7 billion by the end of this

era (year 1800).

From the industrial revolution to World War II: less famines (in

Europe), food prices fell, better sanitation, smaller death rate.

Migration out of Europe. Population around 2.5 billion in 1945.



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3 The present demographic situation



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Source: U.S. Census Bureau, International Population Reports

WP/02, Global Population Profile: 2002, U.S. Government

Printing Office, Washington, DC, 2004.

TFR sources: Sneeringer, Stacy E. 2009. Fertility Transition in

Sub-Saharan Africa: A Comparative Analysis of Cohort Trends

in 30 Countries. DHS Comparative Reports No. 23. Calverton,

Maryland, USA: ICF Macro.

Rutstein, Shea O. 2002. Fertility Levels, Trends, and

Differentials 1995-1999. DHS Comparative Reports No. 3.Calverton, Maryland: ORC Macro.



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Figure 1.

Time to Successive Billions in World Population: 1800-2050The sixth billion accrues to world population in record time!

Source: United Nations (1995b); U.S. Census Bureau, International Programs Center, International Data Base and unpublished tables.

Population in billions Total world population

0

1

2

3

4

5

6

7

8

9

10

205020001950190018501800

1804

1922

1959

1974

1999

1987

2013

2028

2048

20years

15years

14years

12years

13years

15

years37 years

118 years



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Table A-3.

Population, Vital Events, and Rates by Region and Development Category: 2002

[Population and events in thousands. Figures may not add to totals because of rounding]

RegionMidyear

population Births DeathsNatural

increase

Births per1,000

population

Deaths per1,000

population

Rate ofnatural

increase(percent)

WORLD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6,228,394 128,578 54,997 73,581 21 9 1.2Less Developed Countries . . . . . . . . . . . . 5,029,539 115,120 42,794 72,326 23 9 1.4More Developed Countries . . . . . . . . . . . . 1,198,856 13,458 12,203 1,255 11 10 0.1

AFRICA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 838,720 30,133 12,097 18,036 36 14 2.2Sub-Saharan Africa . . . . . . . . . . . . . . . . . . 686,522 26,538 11,285 15,253 39 16 2.2North Africa . . . . . . . . . . . . . . . . . . . . . . . . . 152,199 3,595 813 2,783 24 5 1.8

NEAR EAST . . . . . . . . . . . . . . . . . . . . . . . . . .178,574 4,905 1,071 3,833 28 6 2.1

ASIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3,517,862 68,104 26,671 41,434 19 8 1.2

LATIN AMERICA AND THE

CARIBBEAN . . . . . . . . . . . . . . . . . . . . . . . . . 538,680 11,282 3,256 8,026 21 6 1.5

EUROPE AND THE NEW

I ND EPE ND EN T S TAT ES . . . . . . . . . . . . . 803,255 9,186 8,974 212 11 11 (Z)Western Europe . . . . . . . . . . . . . . . . . . . . . 392,237 4096 3,843 254 10 10 0.1Eastern Europe . . . . . . . . . . . . . . . . . . . . . . 120.864 1,296 1,314 -18 11 11 (Z)New Independent States . . . . . . . . . . . . . . 290,154 3,794 3,818 -24 13 13 (Z)

NORTH AMERICA . . . . . . . . . . . . . . . . . . . . 319,705 4,432 2,701 1,731 14 8 0.5

OCEANIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31,598 536 227 309 17 7 1

EXCLUDING CHINA:

World . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,918,062 111,397 46,250 65,147 23 9 1.3Less Developed Countries . . . . . . . . . . . . 3,720,158 97,966 34,053 63,912 26 9 1.7

Asia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,208,482 50,950 17,929 33,020 23 8 1.5Less Developed Countries . . . . . . . . . . . . 2,081,416 49,725 16,867 32,858 24 8 1.6

Z Between -0.05 percent and +0.05 percent.

Note: Reference to China encompasses China, Hong Kong S.A.R., Macau S.A.R., and Taiwan. Direct access to this table and the International Data Base is availablethrough the Internet at www.census.gov/ipc/www.

Source: U.S. Census Bureau, International Programs Center, International Data Base.



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Figure 2.Regional Distribution of Global Population:1950, 2002, and 2050

Population rankings of major world regionscontinue to shift in favor of developing regions.

* "Developed World" refers to North America (excluding Latin America and theCaribbean), Western Europe, Japan, Australia, and New Zealand. Rest of Asia andOceania refers to Asia excluding Japan, China, and India plus Oceania excludingAustralia and New Zealand. NIS indicates the New Independent States of theformer Soviet Union.** Current boundaries.Source: U.S. Census Bureau, International Programs Center, International Data Base.

Population in millions

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

205020021950**

China Eastern Europe and the NIS

Developed World* Sub-Saharan Africa

India Latin America and the Caribbean

Rest of Asia and Oceania Near East and North Africa



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Table 1.

The Top Ten Most Populous Countries: 1950, 2002, and 2050*

Less developed countries dominate the list of the world's ten mostpopulous countries

1950** 2002 2050

1. China 1. China 1. India

2. India 2. India 2. China

3. United States 3. United States 3. United States

4. Russia 4. Indonesia 4. Indonesia

5. Japan 5. Brazil 5. Nigeria

6. Indonesia 6. Pakistan 6. Bangladesh7. Germany 7. Russia 7. Pakistan

8. Brazil 8. Bangladesh 8. Brazil

9. United Kingdom 9. Nigeria 9. Congo (Kinshasa)

10. Italy 10. Japan 10. Mexico

Rankings of future or past top-ten countries

11. Bangladesh 11. Mexico 14. Russia

13. Pakistan 13. Germany 16. Japan

15. Nigeria 21. United Kingdom 24. Germany16. Mexico 22. Italy 29. United Kingdom

32. Congo (Kinshasa) 23. Congo (Kinshasa) 35. Italy

*More developed countries/less developed countries.**Current boundaries.Source: U.S. Census Bureau, International Programs Center, International Data Base and unpublished tables.



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Total fertility rates (TFR) It is not the average number of children a woman will bear.

It is a synthetic measure.

TFR is the sum of the age-specific fertility rates of women in a

given year.

Age-specific fertility rate: number of births born to women of a

specific-age (15-19, 20-24, etc.)

TFR: number of children an average woman would have in her

lifetime if age-specific fertility rates remained constant.

Captures a current trend.



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0

1

2

3

4

5

6

7

8

9

0 15-19 20-24 25-29 30-34 35-39 40-44 45-49

Numberofbirths

Age Group

Figure 3.1: 23 Sub-Saharan African countries: Cumulative number of births,by mother's age and birth cohort

Cohort 1940-1949

Cohort 1950-1959

Cohort 1960-1969

Cohort 1970-1979



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0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

15-19 20-24 25-29 30-34 35-39 40-44 45-49

Averagenumberofbirthsperwom

anintheagegroup

Age group

Fig. 3.2: 23 Sub-Saharan African countries:Age-specific fertility rates, by mother's birth cohort

Cohort 1940-1949

Cohort 1950-1959

Cohort 1960-1969

Cohort 1970-1979



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BrazilColombia

Dominican RepublicPeru

NicaraguaBolivia

HaitiGuatemala

VietnamKazakhstan

IndonesiaIndia

BangladeshKyrgyz Republic

UzbekistanPhilippines

Nepal

TurkeyEgypt

JordanYemen

South AfricaZimbabwe

Ghana

KenyaComoros

NigeriaCameroon

entral African Republic

TogoCte dIvoireMozambique

TanzaniaGuinea

Senegal

EritreaMadagascar

ZambiaBenin

Burkina FasoTchad

MaliUganda

Niger

0.0 2.0 4.0-2.0-4.0-6.0-8.0

TFR 0-3 years before surveyChange in TFR between 0-3and 4-7 years before survey

8.0 6.0 4.0 2.0 0.0 -2.0 -4.0



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Figure 9.

Total Fertility Rate Relative to the Replacement Level for Each Country Across the Globe: 2002

In 2002, fertility levels were highest in the countries of Sub-Saharan Africa andthe Near East, and lowest in the more developed countries.

Source: U.S. Census Bureau, International Programs Center, International Data Base and unpublished tables.

Below replacement

Less than 1 child per womanabove replacement

1-2 children per womanabove replacement

3 or more children per womanabove replacement

Not available



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Figure 18.Age-Sex Structure of Global Population: 2002

The globe's population in 2002 wasrelatively young.


400 300 200 100 0

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+

100 200 300 400

Male FemaleAge

Millions



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Figure 19. Population Pyramids by Region and Selected

Countries: 2002

9 8 7 6 5 4 3 2 1 0

0-45-9

10-1415-1920-2425-29

30-3435-3940-4445-4950-5455-5960-6465-6970-7475-79

80+

1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 0

0-45-9

10-1415-1920-2425-29

30-3435-3940-4445-4950-5455-5960-6465-6970-7475-79

80+

1 2 3 4 5 6 7 8 9

Male Female Male FemaleAge Age

Sub-SaharanAfricaWorld

Developed WorldWorld

9 8 7 6 5 4 3 2 1 0

0-45-9

10-1415-1920-2425-2930-3435-3940-4445-49

50-5455-5960-6465-6970-7475-79

80+

1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 0

0-45-9

10-1415-1920-2425-2930-3435-3940-4445-49

50-5455-5960-6465-6970-7475-79

80+

1 2 3 4 5 6 7 8 9

Age Age

ChinaWorld

IndiaWorld



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Figure 19. Population Pyramids by Region and Selected

Countries: 2002


9 8 7 6 5 4 3 2 1 0

0-45-910-14

15-1920-2425-2930-3435-3940-4445-4950-5455-5960-6465-6970-7475-79

80+

1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 0

0-45-910-14

15-1920-2425-2930-3435-3940-4445-4950-5455-5960-6465-6970-7475-79

80+

1 2 3 4 5 6 7 8 9

9 8 7 6 5 4 3 2 1 0

0-45-9

10-1415-1920-2425-29

30-3435-3940-4445-4950-5455-5960-6465-6970-7475-79

80+

1 2 3 4 5 6 7 8 9 9 8 7 6 5 4 3 2 1 0

0-45-9

10-1415-1920-2425-29

30-3435-3940-4445-4950-5455-5960-6465-6970-7475-79

80+

1 2 3 4 5 6 7 8 9

Percent of total population Percent of total population

Age Age

Age Age

Rest of Asia andOceaniaWorld

Near East andNorth AfricaWorld

Latin America andthe CaribbeanWorld

Eastern Europeand the NISWorld



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4 The causes of population growth



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4.1 Malthus, the Pessimist Population expansion is limited by food supply.

If wages increase, people will marry younger and have more

children but this will be temporary.

Because resources are fixed, population growth will lead to

unemployment and a later reduction in wages.

With lower wages, fertility will go back to its initial level.

Famines occur when population does not adjust fast enough to

the changes in wages.

Question: Is Malthus missing something here?



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4.2 Modern theories

Fertility is the outcome of supply and demand forces.

Supply: think of programs reducing the cost of contraceptives.

Demand: children could seen as having an economic and

psychic benefit for parents.

For example, in agriculture children are another source of labor.



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Hypotheses:1. Fertility should be higher when young children can earn income

or contribute to household activities than when they cannot.

2. Reducing infant death should lower fertility because fewer births

are needed to obtain the desired number of children.3. A social security system for the elderly should lower fertility

reducing the need for parents to depend on their children for

support in their old age.

4. Increasing opportunities to women in the job market could

decrease fertility.

5. Fertility may increase with family income.



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5 Population and development



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5.1 Population and accumulation Coale and Hoover:

With lower fertility, less investment is needed to provide a

constant amount of capital per worker.

Resources can be allocated away from education and health(due to fewer children) in favor of physical capital.

Slower population growth would lower dependency ratio

which in turn would reduce consumption and increase

savings.

Do you agree with this hypothesis? Think about the Solow

model.



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5.2 Population and productivity

Malthus and neo-Malthusians: science and technology cannot

resolve the key problems of diminishing returns.

Population optimists

Possibility to exploit economies of scale: returns to

investment in roads and education are higher (up to a

point) with more population.

Population pressures could induce technological change.

More people means more entrepreneurs and more creators.

Do you agree?



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5.3 Population and market failures

Key issue: fertility is a decision made by rational individuals.

Why then these individuals creating such a pressure on

resources?

Market failures: costs and benefits of actions/behaviors arenot fully borne by actors.

So families have more children but fail to internalize the cost

(their) children might have on public services (e.g., education

and health). But the root cause of the problem is the slow speed of the

public provision of these services not population itself.



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Other issues:

Optimal and observed demand for children and the marketfor contraceptives (see homework 3).

Quantity-quality trade-off?



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6 Population policy



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Policy alternatives Family planning programs: make contraceptive methods more

available or cheaper.

Reproductive health.

Sterilization programs.

Incentives: educating girls, bribing parents as in Indonesias

program.

Income, development and family planning. Can development

be the best contraceptive?

See homework 3.


Documents

5. Population