Chapter 3Chapter 3

Key Issue 3Key Issue 3

Why is population increasing at Why is population increasing at different rates in different countries?different rates in different countries?

Demographic Transition ModelDemographic Transition Model

All countries have All countries have experienced some experienced some changes in natural changes in natural increase, fertility, and increase, fertility, and morality rates at different morality rates at different times and at different times and at different rates.rates.

Although rates vary Although rates vary among countries, a similar among countries, a similar process of change is process of change is operatingoperating

Because of local cultural Because of local cultural and economic conditions, and economic conditions, the demographic the demographic transition diffuses to transition diffuses to individual countries at individual countries at different ratesdifferent rates

Demographic Transition ModelDemographic Transition Model

Stage 1: Low GrowthStage 1: Low Growth HIGH BIRTH and DEATH HIGH BIRTH and DEATH

ratesrates Most of Humanity’s Most of Humanity’s

occupancy on earthoccupancy on earth People depended on People depended on

Hunting/GatheringHunting/Gathering Food supplies were Food supplies were

unpredictableunpredictable WarWar Disease- no modern Disease- no modern

medicinemedicine Pre- Industrial RevolutionPre- Industrial Revolution NO COUNTRY STILL IN NO COUNTRY STILL IN

STAGE ONE!!!!STAGE ONE!!!!

Stage 2: High GrowthStage 2: High Growth

Death rate drops, Birth Rate Death rate drops, Birth Rate stays highstays high Occurred in most countries during Occurred in most countries during

1818thth and 19 and 19thth centuries, during the centuries, during the Industrial Revolution.Industrial Revolution.

Improved sanitation/hygieneImproved sanitation/hygiene Improved medical practicesImproved medical practices More food available/ new technologyMore food available/ new technology

CBR high, NIR high = rapid growthCBR high, NIR high = rapid growth

MDC’s went through stage 2 by MDC’s went through stage 2 by 1800’s1800’s LDC’s didn’t start in stage 2 until LDC’s didn’t start in stage 2 until

1950’s1950’s Thanks to medical revolutionThanks to medical revolution

Several periphery nations still in Several periphery nations still in Stage 2Stage 2

Stage 3: Moderate GrowthStage 3: Moderate Growth

Birth rate begins to Birth rate begins to drop, death rate lowdrop, death rate low Pop still grows because Pop still grows because

CBR still higher than CDRCBR still higher than CDR NIR slowsNIR slows

MDC’s moved into stage MDC’s moved into stage 3 in early 1900’s3 in early 1900’s

Most Asian and Latin Most Asian and Latin American countries todayAmerican countries today

Sudden drop of birth rates Sudden drop of birth rates due to changes in social due to changes in social customs customs

Economic changesEconomic changes Urban societiesUrban societies

Stage 4: Low GrowthStage 4: Low Growth

Reaches stage when zero Reaches stage when zero population growth is population growth is achieved. achieved. BR=DRBR=DR NIR = 0NIR = 0

Called zero population growth Called zero population growth (ZPG)(ZPG)

below replacement levelbelow replacement level Mainly Europe and United Mainly Europe and United

StatesStates Changes in lifestyle encourage Changes in lifestyle encourage

small familiessmall families

Countries that have NEGATIVE Countries that have NEGATIVE growth: growth: Russia and other Eastern Russia and other Eastern

European CountriesEuropean Countries Cause: Communist RuleCause: Communist Rule

55thth stage? stage?

Not identified yetNot identified yet

Characterized by higher Characterized by higher CDR than CBRCDR than CBR

Irreversible population Irreversible population declinedecline Japan?Japan? Italy?Italy? Russia?Russia?

ENGLAND EXAMPLEENGLAND EXAMPLE Stage 1Stage 1

Pre-1750Pre-1750 Norman invasion 1066Norman invasion 1066 Population = 1 millionPopulation = 1 million Black deathBlack death Famines/ bad harvestsFamines/ bad harvests

Stage 2Stage 2 1750: CBR and CDR -401750: CBR and CDR -40 By 1800: CBR 34, CDR 20By 1800: CBR 34, CDR 20

Industrial RevolutionIndustrial Revolution NIR 1.4% , pop increased from 6- 30 millNIR 1.4% , pop increased from 6- 30 mill

Stage 3Stage 3 After 1880After 1880

CBR declined sharplyCBR declined sharply Between 1880- 1970 pop only increased .7 % Between 1880- 1970 pop only increased .7 %

per yearper year

Stage 4Stage 4 Since 1970sSince 1970s

CBR/ CDR evenCBR/ CDR even TFR below replacement TFR below replacement

levelslevels

EXAMPLESEXAMPLES

CapeCape Verde: Verde: Chile: Stage 3 Chile: Stage 3 DenmarkDenmark

stage 2stage 2 stage stage 44

WHY ISN”T EVERY COUNTRY AT WHY ISN”T EVERY COUNTRY AT STAGE 4????STAGE 4????

Demographic changeDemographic change Sudden decline in CDRSudden decline in CDR

Core nations:Core nations: Industrialization led to Industrialization led to

wealthwealth Wealth led to scientific Wealth led to scientific

innovationsinnovations

Semi/ Periphery nations:Semi/ Periphery nations: Diffusion of scientific and Diffusion of scientific and

technological innovationstechnological innovations All have accepted All have accepted

technology (vaccines, technology (vaccines, medications, etc.)medications, etc.)

BUT….not all countries BUT….not all countries have “changed” social have “changed” social customscustoms

Demographic Transition and World Demographic Transition and World Population GrowthPopulation Growth

Huge population Huge population explosion during 2explosion during 2ndnd ½ ½ of 20of 20thth century century No country in stage 1, No country in stage 1,

few in stage 4few in stage 4

CausesCauses Drop in DR b/c of Drop in DR b/c of

technologytechnology Drop in BR b/c of change Drop in BR b/c of change

in social customin social custom

Population PyramidsPopulation Pyramids

A population pyramid is a bar A population pyramid is a bar graph that displays age and graph that displays age and gender of a populationgender of a population Males on left, females on rightMales on left, females on right 5 year age groups5 year age groups Shape determined by CBRShape determined by CBR

Demographic transition gives Demographic transition gives a country a distinctive a country a distinctive population structurepopulation structure

Influenced by:Influenced by: % of Population in each age group% of Population in each age group Distribution of Male and FemalesDistribution of Male and Females

Age DistributionAge Distribution

Most important factor is Most important factor is dependency ratiodependency ratio::

# of people too old or # of people too old or young to work compared young to work compared to the # of people in their to the # of people in their productive yearsproductive years

Three age groups:Three age groups: - 0 – 14- 0 – 14 - 15 – 64- 15 – 64 - 65 +- 65 +

½ of all people in stage 2 ½ of all people in stage 2 countries (LDCs/ countries (LDCs/ Periphery) are Periphery) are dependentdependent Mainly youngMainly young

1/3 of all people in 1/3 of all people in MDC’s (Core) are MDC’s (Core) are dependentdependent Mainly oldMainly old

ProblemsProblems

The large amount of Children in Africa The large amount of Children in Africa strain resourcesstrain resources

““graying” populations of U.S. and Europe graying” populations of U.S. and Europe are burdens on the governmentare burdens on the government

Sex RatioSex Ratio

# of males# of males

per hundred per hundred

FemalesFemalesStage 2 countries Stage 2 countries

have low % of have low % of women due to women due to childbirth deathschildbirth deaths

Population PyramidsPopulation Pyramids

Allows demographers Allows demographers to identify changesto identify changes

Population cohortsPopulation cohorts Group of individuals who Group of individuals who

share a common share a common temporal demographic temporal demographic experience experience

Example:Example: Deficit of births after a Deficit of births after a

warwar

Population Pyramid PracticePopulation Pyramid Practice