lecture1 popboom&bust

Lecture 1:

Population Boom and Bust: Population Change in

Developing and Developed Countries

Source: National Geographic Survey, 1988

Outline World population growth

by region, over time, projections,

Formula for population change

Population growth in the USA

Demographic transition theory

Age distribution changes

Urbanization

Population growth and economic growth

Global Population Growth

World Population Growth, 1750-2050

8

Class participation

Additions of population to the planet in real time.

Population growth in real time(visual display of same)

http://www.worldometers.infohttp://www.census.gov/popclock/?

intcmp=home_pop

TOP 10 CONTRIBUTORS TO WORLD POPULATION GROWTH (NET ANNUAL ADDITIONS) 2010-2015

No. Country Net addition (in millions)

1 India 16.0

2 China 7.0

3 Nigeria 4.6

4 Pakistan 3.8

5 Indonesia 3.2

6 USA 2.4

7 Ethiopia 2.4

8 Dem. Rep. of Congo

2.3

9 Egypt 1.9

10 Bangladesh 1.9

Top 10 45.5

World total 83.9

Source: UN Population Division. World Population Prospects, 2015 Revision.

Population Trends by Region 1950-2050

0

1

2

3

4

5

6

Asia Africa LatinAmerica

Europe NorthAmerica

Bill

ion

s

195020002050 (projection)

Source: United Nations 2001

Projections

http://www.un.org/esa/population/unpop.htm

Source: UN Pop Div: http://esa.un.org/unpd/ppp/Documentation/highlights.htm

Source: Population Division, Population Estimates, and Projection Sections .United Nations, Department of economic and Social Affairs

0

2

4

6

8

10

12

Po

pu

lati

on

(in

bil

lio

ns)

Year

Population of the world,1950-2050, according to different projection variants

Medium

High variant

Low variant

Constant-fertility variant

Population Division, Population Estimates, and Projection Sections .United Nations, Department of economic and Social Affairs

The Uncertainty of Population Forecasts

Source: NRC, 2000. Beyond Six Billion.

How many years did it take to add the last billion people to the world population?

a. 12

b. 18

c. 20

d. 24

e. 30

Rates

Crude birth rate = CBR =1000* Births/Midyear pop.

Crude death rate = CDR =1000* Deaths/Midyear pop.

Crude rate of natural increase = CRNI = CBR-CDR

25

Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

Rates of birth, death, and natural increase per 1,000 population

0

5

10

15

20

25

30

35

40

1950-1955

1955-1960

1960-1965

1965-1970

1970-1975

1975-1980

1980-1985

1985-1990

1990-1995

1995-2000

2000-2005

Birth rate Death rate

Natural Increase

© Population Reference Bureau 2006.

01

02

03

04

05

06

07

08

09

01

00P

op

adde

d pe

r ye

ar (

mill

ion

s)

1950 1960 1970 1980 1990 2000 2010year

Source: UN Pop. Div.

Millions of persons added to the planet per year 1950-2015

“Pair and share:” How is it possible for absolute numbers of births to increase even when

birth rates are declining?

Equations for population change

1. Bookkeeping equation

Pt = Po + B – D + I – O Note: I = In-migrants; 0 = out-migrants

2. Linear equation

Pt = Po + k*t k = number added per year t = number of years

Exponential Growth Rate

• Exponential growth rate

Pt = Po * exp(r*t) solving

• The advantage of the exponential method is that it’s easy to solve for any parameter

PP

ln t1

r0

t

r

PP

ln

t 0

t

rtt

0e

PP

Math problem

If we know the growth rate ‘r’, how could we find the doubling time? What is a simple answer?

Question: What is the only sustainable population

growth rate in the long term?

Population growth rate by centuryra

te

Centuriesx

0 10 20 30 40 50 60 70 80 90 100

0

2

Rate of Population Growth

0.48

0.65

1.111.48

1.951.78

0

0.5

1

1.5

2

2.5

1950 1970 1990 2010 2030 2050

Annual percent increase in world population, 1950-2050

Source: UN, World Population Prospects: The 1996 Revision, 1998 (medium scenario).

2.04

FIVE COUNTRIES WITH THE HIGHEST AND FIVE COUNTRIES WITH THE LOWEST RATES OF NATURAL INCREASE 2005-2010

Highest rates Lowest rates

Country or area Rate ofnaturalincrease(percentage)

Country orarea

Rate ofnaturalincrease(percentage)

Niger 4.02 Bulgaria -0.57

Gambia 3.38 Lithuania -.0.50

Mali 3.34 Latvia -0.46

Uganda 3.34 Ukraine -0.45

Burundi 3.25 Hungary -0.38

Source: United Nations, Population Trends

If a population has doubled in size in the last 23 years, we can estimate the average annual rate of

growth over that time was:

a. 6 percent per yearb. 4 percent per yearc. 3 percent per yeard. 2 percent per yeare. 1 percent per year

Conclusion:

We live in a very demographically

divided/diverse world!

Population Growth in the U.S.A.

U.S. Population Growth

• Net immigration About 1 million new legal immigrants Maybe 300,000 net undocumented Relatively small number of emigrants

• Approximately 4.0 million births

• Approximately 2.6 million deaths

• NET GROWTH= ABOUT 2.4 -2.7 MILLION

Sources: Migration Policy Inst., 2015; Pew Center, 2012; US Census Bureau, 2014

Our local area

Source: http://www.inliquid.com/artist/oliva_daniel/oliva.phpphoto 6: Baltimore/Washington, from Composite Views series, 2007, 12” x 16”

http://www.inliquid.com/artist/oliva_daniel/oliva.php

Maryland counties

Source: http://www.google.com/search?q=map+of+maryland+counties&hl=en&prmd=imvns&tbm=isch&tbo=u&source=univ&sa=X&ei=HGJOUP_yEerk0QHluoDQCQ&ved=0CB0QsAQ&biw=1024&bih=566

050

100

150

200

250

300

350

pop1

1940 1950 1960 1970 1980 1990 2000 2010 2020 2030 2040year

Pop

ulat

ion

in th

ousa

nds

and projections to 2030Population of Howard Country, Maryland 1950-2000

Is rapid population growth a

problem?

In the long term definitely yesand maybe in the short term

Is population decline a problem?

In the long term definitely yes, but in the short term not necessarily

Demographic Transition

Stages of the demographic transition

1. High birth and death rates, zero or low growth

2. Death rates declining, birth rates still high so high growth rate

3. Death rates and birth rates both declining and growth rate declining

4. Both birth and death rates low so zero or low growth

Demographic Transition

birth rate

growth rate

death rate

05

10

15

20

25

30

35

40

1850 1860 1870 1880 1890 1900 1910 1920 1930 1940year

Eve

nts

pe

r th

ousa

nd

pop

ula

tion

1850 to 1940Births and deaths per 1000 population in Germany

Demographic Transition (Omran, 1971)

The transition in Sweden

During the second stage of the demographic transition, there is rapid population growth

because:

a. Death rates begin to fall while birth rates remain high

b. Birth rates begin to rise while death rates remain steady

c. Birth and death rates are falling together

d. Birth and death rates are both very high

Why Population Growth Continues in the Developing World

Fertility remains above the replacement level (Note: replacement fertility is about 2 children per woman)

Declining mortality

Population momentum due to a young age structure

Population momentum

Definition of momentum: The ratio of ultimate population size to current population size if fertility immediately declines to replacement level. (NOTE: We teach the mathematics of this in our advanced demographic methods course at JHSPH)

Population momentum in Japan

Population Momentum

Uganda Example

(Source: Spectrum program)

From colleague Pf Mosley

1) High fertility Strengthen family

planning programs

Causes of Growth

Policy Options

2) Declining mortality

3) Momentum of population growth

Delay childbearing

Invest in human capital

- Wanted

- Unwanted

***Note we will define wanted and unwanted fertility in a future lecture

Another way to counteract the effect of momentum:

Below replacement fertility

e.g. one child family norm

Age composition changes

Population Structures by Age and Sex, 2005: Age pyramidsMillions

300 100 100 300300 200 100 0 100 200 300

Less Developed Regions

More Developed Regions

Male Female Male Female

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

Age

Source: United Nations, World Population Prospects: The 2004 Revision, 2005.

Age Distribution of the World’s Population

Copyright: Population Reference Bureau, 2006.

Population by Age: Developing World

0 200 400 600 800

0-4

10-14

20-24

30-34

40-44

50-54

60-64

70-74

Ag

e

Population (millions)Source: United Nations 2001

1950 1975 2000 2025 2050

Urbanization

Varied definitions of urban

Country Definition

Ethiopia 2000 or more inhabitants

Senegal 10,000 or more inhabitants

Swaziland localities proclaimed as urban

Mexico areas with over 2500 inhabitants

Greenland localities with 200 or more inhabitants

Canada 1000 inhabitants with density of 400+ personsper sq. km.

Indonesia places with urban characteristics

Peru localities with 100 or more dwellings

Austria communes with over 5000 inhabitants

Source: Demographic Yearbook, 2005

Can you name the 5 largest urban agglomerations:

In 1950?In 2015?

urban

rural

12

34

56

7B

illio

n

1950 1960 1970 1980 1990 2000 2010 2020 2030 2040 2050Year

Urban and rural populations of the world (in billions) 1950-2050

Urban PopulationPercent

29

15 17

53

47

37 37

76

55

42

74

85

54

61

82

World Africa Asia Latin Americaand the

Caribbean

MoreDeveloped

Regions

1950 2000 2030

Source: United Nations, World Urbanization Prospects: The 2003 Revision (medium scenario), 2004.

Trends in Urbanization, by Region


Source: United Nations, 2008. World Urbanization Prospects: The 2007 Revision

Percentage of population living in urban areas, 2050

Population and Development

Association Between Average Annual World Population Growth Rates and GDP per Capita Growth Rates, 1975-2004

-1

0

1

2

3

4

5

6

7

8

-6 -4 -2 0 2 4 6 8

Growth Rates in Population

Source: Population Reference Bureau, Population & Economic Development Linkages 2007 Data Sheet.

Growth Rate in GDP per Capita

Growing population

Growing economyDeclining population

Declining economy

China

SingaporeCongo, Dem. Rep.

Saudi Arabia


• Globally, a higher rate of population growth is associated with a lower rate of economic growth, but the association varies across regions and income levels and it was the reverse association in the 1970s and 1980s.


Association Between Average Annual Growth Rates in Population and GDP per Capita, Africa, 1975-2004

-1

0

1

2

3

4

5

6

7

8

-10 -5 0 5 10 15

Population Growth Rate


GDP per Capita Growth Rate

Growing population

Growing economyDeclining populationDeclining economy

Botswana

Lesotho

Sierra Leone


Association Between Average Annual Growth Rates in Population and GDP per Capita, Asia, 1975-2004

-1

0

1

2

3

4

5

6

7

8

-10 -5 0 5 10 15

Population Growth Rate


GDP per Capita Growth Rate

Growing population

Growing economyDeclining populationDeclining economy

China

Kuwait Malaysia


Literacy Rates, by Sex, 2000-2004Percent

77

53

89

73

55

87

70

9186

77

World Sub-SaharanAfrica

Latin Americaand the

Caribbean

Asia Arab States

Female Male

Source: UNESCO Institute for Statistics: accessed online at www.uis.unesco.org/TEMPLATE/html/Exceltables/education/Literacy_Regional_April2006.xls on May 21, 2006.

Adult Literacy, by Region


Percent of population living on less than $2 per day

Source: UN Human Development Report 2009

Note: Territory size shows the proportion of all people living on less than or equal to US$2 in purchasing power parity a day.

Proportion of the population living on less than or equal to $2 per day

Source: http://www.worldmapper.org/display.php?selected=180

Questions/Things to know

In what region do most of the people of the world live?

Which region has the highest population growth rate?

What is the world population size in 2014?About how many people are added to the

planet each year?What is the bookkeeping equation of

population change?

Questions (cont.)

What is the simple rule to find doubling time given the rate of growth?

Name two countries in the top 5 with highest rate of natural increase

Name two countries in the top 5 with lowest rate of natural increase

Approximately how much is the US population growing each year?

About what proportion of US growth is due to immigration?

Questions (cont.)

What are the 4 stages of the demographic transition?

Why is population momentum an important concept for countries concerned about population growth in the future?

Name two of the largest cities (urban agglomerations) in the world in 1950. In 2010?

lecture1 popboom&bust

Documents

population division

population estimates

population boom

world population prospects

world total

national geographic

pop div

department of economic