POPULATION

Bell Work – Population & Demography 2/3

What does this graph show?

What is the message of this political cartoon?

What happened between 1600 & 1900 that could have cause the population to increase so dramatically?

3 REASONS STUDYING POPULATION IS CRITICAL

More people are alive today than at any other time in human history

The world’s population increased at a faster rate during the second half of the twentieth century than every before.

Virtually all population growth today occurs in less developed countries (LDCs)

QUESTIONS TO ASK ABOUT POPULATION

Why is the population growing so quickly?

Which areas are growing fastest?What effects has this growth had on social and ecological systems?

What can we expect from future growth?

These questions = Population Geography also known as Geodemography

The study of human populations = demography

THE PROBLEM IS THAT POPULATION IS LIKE COMPOUND INTERESTLets say you invest a $1,000,000 in a bank account that is guaranteed a minimum of 3% interest

The next year you would then have $1,030,000

And the next year you would have $1,060,900

And the next $1,092,727

$25 years… later $2,088,626.81

With a 3% growth rate the U.S population would double by then time you were 42 which means 300,000,000x2= 600,000,000

If the population of the U.S doubles what else needs to double?

What are some reasons this probably won’t happen here?

The actual growth rate is .7

However! The growth rate in Africa, the Middle East & Central America are all above 3%

WHERE IS THE WORLD’S POPULATION DISTRIBUTED?Population concentrations

• Two-thirds of the world’s population are in four regions:

• East Asia (1/4 of world pop, 5/6 of this in China)• South Asia (1/4 of world pop, ¾ of this in India)• Europe (1/9th of the world pop, mostly in cities)• Southeast Asia (600 million, mostly in islands)

• 80% of the worlds population lives in LDCs• Not to mention that over the past 50 years the global life expectancy has increased from 45 to 65 years

CARTOGRAMS

Cartograms are not usually useful for exact measures of population, however they do illustrate the point clearer than some other maps (think of the ones you did a while back with the substitute

What’s the difference in terms of concentration & density of china compares to the U.S?

WHERE IS THE WORLD’S POPULATION DISTRIBUTED?

Sparsely populated regions

• The ecumene (portion of the world’s surface occupied by permanent human settlement)

• People generally avoid:• Dry lands• Wet lands• Cold lands• High lands

WHERE IS THE WORLD’S POPULATION DISTRIBUTED?

Population density

Arithmetic density – the number of people living in a given area• Most frequently used• More accurate the smaller the area observed• Tells us WHERE, but not WHY people live in an area (we must have more info for

that)

Physiological density

- A ratio of human population to the area of arable land

• The greater the physiological density, the more stress those people put on the land to produce crops

• Gives us insight as to the available resources of an area

• If you compare the arithmetic density to the physiological density, you can infer how much of the area’s land is unsuitable for agriculture

Physiologic Population Density Luxor, Egypt. Egypt’s arable lands are along the Nile River Valley.

Moving away from the river a few blocks, the land becomes sandy and wind-sculpted.

Agricultural density – ratio of the number of farmers/arable land• High # of farmers=low technology• Low # of farmers=high technology• Comparing Physiological to Agricultural density shows the

relationship between the population of a country and its resources

POPULATION

KEY ISSUE #2 – WHERE HAS THE WORLD’S POPULATION INCREASED?

NATURAL INCREASECrude Birth Rate (CBR) = Total # of births in a year for every 1,000

Crude Death Rate (CDR) = Total # of deaths a year for every 1,000

Natural Increase Rat (NIR) =% by which a population grows each year CBR-CDR=NIR

What affects a nations natural increase?

Economic development

Education

Gender Empowerment

Healthcare

Cultural Traditions

Public Policy

To predict how much a population will grow we use the demographic accounting equation

The Demographic Accounting Equation

Pop(t+1) = Pop(t) + B – D + MI - Mo

Pop(t+1) = Population in time t+1, the year following the current year.

Pop(t) = Population in time t, the current. B = BirthsD = DeathsMI = In-migrantsMo = Out-migrants

• (B-D) = Natural Increase• (MI-MO) = Net Migration

Example

Pop(t+1) = Pop(t) + B – D + MI - Mo

Russia

Pop(t) = 1,000 Births = 12/1,000Deaths = 15/1,000MI immigrants = 22/1,000Mo emigrants = 20/1,000

Pop(t+1) = 1,000 + (12 – 15) + (22 – 20)

Pop(t+1) = 1,000 - 3 + 2 = 999

• Natural Increase = (12-15) = -3• Net Migration = (22-20) = 2

FERTILITY & MORTALITY

Total Fertility Rate (TFR)= measures the # of births in a society

World TFR = 2.6 TFR in Africa= 6 TFR in Europe=1.9

Infant mortality Rate (IMR)= Annual number of deaths for infants under 1

MDCs= lower NIRs, CBR, IMR &TFR with higher Life expectancy

LDCs= higher NIRs, CBR, IMR & TFR with lower life expectancy

NIR

CBR

FERTILITY RATE

IMR

CDR- DOES NOT FOLLOW THE SAME PATTERN

Some very wealthy countries have a higher CDR then some of the poorest

Examples:

Denmark has a higher CDR than Cape Verde

The U.S has a higher CDR than nearly every country in Latin America

How could this be?

BELL WORK 2/5

If a country has a high CDR & high CBR, what can we say about this countries level of technology? Level of development? Are they an MDC or LDC?

If a country has a low CDR & CBR what can we say about this countries level of technology? Level of development? Are they an MDC or LDC?

THE DEMOGRAPHIC TRANSITION MODELStage 1 Stage 2 Stage 3 Stage 4 Stage 5?

Low Growth High Growth Moderate Growth Low Growth Declining?

Sources: B.R. Mitchell, European Historical Statistics 1750-1970 (1976): table B6; Council of Europe, Recent Demographic Developments in Europe 2001 (2001): tables T3.1 and T4.1; CELADE, Boletin demografico 69 (2002): tables 4 and 7; Francisco Alba-Hernandez, La poblacion de Mexico (1976): 14; and UN Population Division, World Population Prospects: The 2002 Revision (2003): 326.

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1775 1800 1825 1850 1875 1900 1925 1950 1975 2000

SwedenBirth Rate

Death Rate

MexicoBirth Rate

Death Rate

Births/Deaths per 1,000

1750

BELL WORK POPULATION PYRAMIDS-2/9

Dependency ratio-the number of people who are too young or too old to work compared to the number of people old enough to work.

Replacement Rate- the totally fertility rate (TFR) needed for a population to replace itself. Varies by country, but for most of the developed world it is 2.1

Doubling time The number of years needed to double a population (exponential when it remains the same)

POPULATION AFFECTED BY DEMOGRAPHIC TRANSITION

1. The % of the population in each age group

2. The distribution of males and females

POPULATION DILEMMAS ACTIVITY

You and your group have been given one of 3 population dilemmas that are currently affecting Europe. Follow the directions in the packet you picked up at the beginning of class to complete this activity.

First! – You should brainstorm three answers to the question your group is facing

Second! – you should read through your article and answer the second question

Third!- finish the sentence at the bottom

Fourth!- Repeat steps 1 and 2 for the other side of your dilemma sheet

TAKE OUT THE SHEET FROM FRIDAY

What stage of the demographic transition is each country facing?

What is one positive impact of the population structure on its economic development?

What is one negative impact of the population structure on its economic development?

Stage 2 - Expanding – high birth rate, low life expectancy

Positives- expanding workforce

- youthful population

- less need for immigrant labor

- less need for elder safety net

Negatives- high youth dependency ratio

- strain on resources

Stage 4 – Contracting – low birth rate, high life expectancy

Positives- educated workforce

- low youth dependency ratio

- may need immigrant labor which allows for citizens to take higher paying jobs

Negatives- high elderly dependency ratio

- future labor shortages

- Greater need to fund social security

Stage 5 – Declining – small youth population, low birth rate

Positives- Need for immigrant labor means higher paying jobs for citizens

- immigrants bring new ideas

Negatives- high elderly dependency ratio

- labor shortage

- inability to care for elderly

In 1798 he published An Essay on the Principle of Population

Malthus was the first to sound the alarm that the world’s population was expanding more rapidly than food production.

He was the first to recognize exponential or geometric population growth.

Today those who share his concerns are Neo-Malthusians

Rev. Thomas Malthus 1766-1834

WORLD POPULATION GROWTH

Figure 2-8

WHERE HAS THE WORLD’S POPULATION INCREASED?Fertility

• Total fertility rate (TFR) – average number of children born to a woman over her life

Mortality-Infant mortality rate, child mortality rate, and maternal mortality rate

-Life expectancy (greatly impacted by violence, infant mortality, poor healthcare, epidemic disease, risk factors)