Demography

DemographyTHE STUDY OF POPULATIONS

Explain the significance of changes in world population with reference to population pyramids, distribution,

density, and demographic transition models

© 2006 Population Reference Bureau

A.D.2000

A.D.1000

A.D.1

1000B.C.

2000B.C.

3000B.C.

4000B.C.

5000B.C.

6000B.C.

7000B.C.

1+ million years

8

7

6

5

2

1

4

3

OldStoneAge New Stone Age

BronzeAge

IronAge

MiddleAges

ModernAge

Black Death —The Plague

9

10

11

12

A.D.3000

A.D.4000

A.D.5000

18001900

1950

1975

2000

2100

Future

Billions

Source: Population Reference Bureau; and United Nations, World Population Projections to 2100 (1998).

World Population Growth Through History


Ninth

Eighth

Seventh

Sixth

Fifth

Fourth

Third

Second

First Billion

Number of years to add each billion (year)

All of Human History (1800)

130 (1930)

30 (1960)

15 (1975)

12 (1987)

12 (1999)

14 (2013)

14 (2027)

21 (2048)

Sources: First and second billion: Population Reference Bureau. Third through ninth billion: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

World Population Growth, in Billions


Billions

0

1

2

3

4

5

6

7

8

9

10

1950 1970 1990 2010 2030 2050

Less Developed Regions

More Developed Regions

Source: United Nations, World Population Prospects: The 2004 Revision (medium scenario), 2005.

Growth in More, Less Developed Countries

Why is population growth a problem?

We have seen exponential growth in the world’s population in the past 200 years.

The more people on earth the more resources are required.

Our earth has a limited carrying capacity meaning it can only sustain so many people before its natural systems start to fall apart.

Many scientists believe that we have already exceeded the earth’s carrying capacity:

• mass species extinction• global climate change• air quality• Desertification• loss of fish.

Getting world population under control is one part of the solution to our environmental problems.

Why is it usually the poorer countries who have so many kids and hence high

population growth?

Need for large families (kids need to work)

High infant mortality (kids might die so better have lots)

Low status of women – husbands can have their way = kids

Lack of contraception and education about contraception

Religious opposition to contraception

Lack of pension plans for old people (kids become the pension plan)

First! Some Definitions…Birth Rate (Fertility): The percentage of babies being born in a country relative to its population (annual)(Total live births / Total population) x1000 = Birth Rate

Fertility Rate = average # of children born to a woman over her lifetime

Death Rate (Mortality): The percentage of people who die relative to the country’s population (annual)(Total deaths / Total population) x1000 = Death Rate

Practice:

1. Complete the Birth Rate / Death Rate practice Q’s on your Population Change handout!

Rate of natural increase: Birth rate – Death rateeg., 11% - 7% = 4%

Practice:1.Calculate Canada’s Rate of Natural Increase (%) using

the 1999 data2. Solve the following table:

Country Population (Millions)

Birth Rate per 1000

Death Rate per 1000

Natural Increase per 1000

% Natural Increase

India 1,214,464,000 23.0 8.5Russia 140,367,000 10.8 15.1Gabon 1,501,000 27.5 9.8

Country Population (Millions)

Birth Rate per 1000

Death Rate per 1000

Natural Increase per 1000

% Natural Increase

India 1,214,464,000 23.0 8.5 14.5 1.45%Russia 140,367,000 10.8 15.1 -4.3 -0.43%Gabon 1,501,000 27.5 9.8 17.7 1.77%

Population Change!Immigration: People moving in to another country Emigration: People moving away from their home country.

*If you were to move to England, you would be emigrating from Canada and immigrating into England.*

Why are people moving all over the place? These are called Push-Pull Factors.

Can you think of any?

Practice:

1.Use the data table on your handout to find Canada’s growth rate

SO, there are two things that affect population: Fertility/Mortality rates, and Migration Rates.

Population Growth rate = Rate of natural increase + net migration rate

Doubling Time: The amount of time it takes for a country’s population to double-Generally known as the Rule of 70:

70 / Population Growth Rate = doubling time

Practice:

1.Use the data from the table, calculate how long it will take for Canada’s population to double.

Practice:1. Sketch a curve indicating total population

growth on the DTM on your handout.

The Demographic Transition Model!

The Demographic Transition Model!

• This model predicts that, as a country develops, high birth rates and high death rates will fall.

• This model also predicts that countries will pass through periods of industrialization and urbanization on the way to reduced birth and death rates.

• We will examine each individual stage in the demographic transition model now. Please hold your applause.

Stage OneStage one is characterized by high birth rates and high fluctuating death rates resulting in small population growth. Plagues, diseases and poor nutrition keep mortality high.

Stage Two• Stage two is characterized by improved heath care,

sanitation and increased food supplies leading to a rapid fall in death rates. Birth rates are still high, so there is a rapid increase in population numbers.

Stage Three• Stage three is characterized by a decreased growth rate

of a population. Birth rates begin to fall. Industrialization, urbanization and improved living standards lead to less desire for large families.

Stage Four• Stage four is characterized by the completion of the

transition to a low growth rate with low birth and death rates. The birth rate may fluctuate in special circumstances, such as in the post-war “baby-boom.”

Stage Five• Stage five is characterized by a lower birth than death

rate. This is happening in some European countries and in Japan. It is not known if this trend will extend to other regions.

Population Density

Population Density

The number of people that live in a certain area, for example, per square km. India’s population density is high at 281 people per square km while Canada’s is quite low at 2.8 people per square km. Bangladesh pop dens = 1000 +. Downtown Vancouver pop density = 20000 +

Population DistributionThe pattern of where people live in an area. Closely related to population density.

How can population growth be slowed down?

What a Population Pyramid Tells Us

A population pyramid tells us what portion of a population are within a given age cohort.

70-8060-7050-6040-5030-4020-3010-20 0-10

4 3 2 1 1 2 3 4

Male Female

Population pyramids can also tell us what stage of development a country is at.

Four types of population pyramids

Early expanding

Expanding

Stable

Contracting

Early Expanding •Wide base (lots of young children) and a

very narrow top (few old people).•Very high birth rate and death rate (short

life expectancy).•Reasons could include poor health care,

lack of family planning, need for children as workers.

• Corresponds to stage 1 – 2 of DTM

ExpandingSlightly narrower base than early expanding and a little

wider in the middle and older ages. Birth rate still high but decreasing slightly and death rate

decreasing.Reasons for the change from early expanding could include

better medical care, improved diet and better hygiene. Roughly corresponds with stage three of the demographic

transition model.

Stable: Bottom part of pyramid is close to a vertical line.

Birth rate falls while death rate also falls and they are in balance

Reasons could include better health care, improved family planning, better economic conditions.

Roughly corresponds with stage 4 of the demographic transition model

Japan’s Population Pyramid - 2003

Contracting: Bottom part of pyramid narrower than the middle and

continually getting narrower.Birth rate continues to fall while the death rate continues

to decrease.Reasons could include more women working, high cost of

child rearing, small families encouraged by the state.Examples: Germany/ Japan.

Roughly corresponds with stage 5 of the demographic transition model.


Diverging Trends in Fertility ReductionAverage number of children per woman

5.75.25.4

6.46.4

8.5

5.3

3.3

6.2

3.12.4 2.1

4.3

2.5

Egypt India Indonesia Iran Pakistan Turkey Yemen

1970-1975 2000-2005

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


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

Demography

Education

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