VARIATIONS IN POPULATION GROWTHDEMOGRAPHIC TRANSITION The Demographic Transition

1. Low growth – 3. Moderate growth

2. High growth – 4. Low growth

Population pyramids Age distribution Sex ratio

Countries in different stages of demographic transition

Demographic transition and world population growth

WORLD POPULATION & GROWTH RATES, 400,000 BC - AD 2000

Demographic transition – The changes in natural increase caused by shifts in birth and death rates in a given area of the Earth.

THE DEMOGRAPHIC TRANSITION

Fig. 2-13: The demographic transition consists of four stages, which move from high birth and death rates, to declines first in death rates then in birth rates, and finally to a stage of low birth and death rates. Population growth is most rapid in the second stage.

DEMOGRAPHIC TRANSITION MODEL

Low Growth High

Growth

Moderate

Growth

Low Growth

1) Most of our time on Earth2) High birth and high death rates

NIR is around 0 with population of world around ½ million

3) Food is unpredictable4) Despite beginning of human settlement, war and disease balance out high birth rates (families depend on children for farming)

Present Day: No countries here

1) Industrial Revolution in England and North America (1750-1800)2) High Birth and decreasing death rates3) 10x faster growth4) Stabilization of food supply, improvement of sanitation techniques, and creation of wealth through technology and invention

Present day: 1950 – most of Africa, Asia , Lat. Am.

1) CBR drops, but still is higher than CDR; - CDR continues to decline, but at a slower rate2) CBR declines due to changes in customs, people choose to have fewer children because of changes in female roles, jobs in service/urban areas

Present Day: Beginning of 20th century Europe and North America, most of Asia and Latin America by end of 20th century

1) CBR declines to the point where it equal CDR

2) NIR approaches zero (Zero Population Growth or ZPG)

3) TFR falls beneath the 2.1 replacement rate

4) Women enter the workforce, more access to birth control methods, more leisure/entertainment time

Present Day: Much of Europe, Russia as example

•Stage 5?•High CDR and irreversible population decline

Stag

e 1

Stag

e 4

Stage 2Stage 3

1) Most of our time on Earth2) High birth and high death rates

NIR is around 0 with population of world around ½ million

3) Food is unpredictable4) Despite beginning of human settlement, war and disease balance out high birth rates (families depend on children for farming)

Present Day: No countries here

Stage 1

Back

Stage 21) Industrial Revolution in England and North America (1750-1800)2) High Birth and decreasing death rates3) 10x faster growth4) Stabilization of food supply, improvement of sanitation techniques, and creation of wealth through technology and invention

Present day: 1950 – most of Africa, Asia , Lat. Am.

Back

Stage 31) CBR drops, but still is higher than CDR; - CDR continues to decline, but at a slower rate2) CBR declines due to changes in customs, people choose to have fewer children because of changes in female roles, jobs in service/urban areas

Present Day: Beginning of 20th century Europe and North America, most of Asia and Latin America by end of 20th century

Back

Stage 41)CBR declines to the point where it equal CDR2) NIR approaches zero (Zero Population Growth or ZPG)3) TFR falls beneath the 2.1 replacement rate4) Women enter the workforce, more access to birth control methods, more

leisure/entertainment time

Present Day: Much of Europe, Russia as example

Back

DEMOGRAPHIC TRANSITION IN ENGLAND

Low growth until 1750 – bubonic plague causes a decline as does famine, bad harvests

High growth 1750—1880 industrial revolution food supply is more stable, money though industrial employment

Moderate growth 1880-1970s –

Low growth now now has 50 million vs 6 mil in 1st stageFig. 2-14: England was one of the first countries to experience rapid population growth in

the mid-eighteenth century, when it entered stage 2 of the demographic transition.

BASIC PATTERNS OF POPULATION GROWTH

Stage of demo transition gives it a specific shape

Mostly determined by the CBR Dependency ratio-the number

of people who are too young or too old to work compared to the number of people in their productive years – usually divided into 3 groups 0-14, 15-64, 65 older

Stage 2 1 worker for every dependent, stage 4 2 workers for every 1 dependent

Elderly percentage increases as you move through the stages

Stage 4 countries have higher cdrs because population is older

PERCENT OF POPULATION UNDER 15

1/3rd of the world population is under 15

Sex ratio – number of males /100 females; more males than females are born, but men die earlier in Europe/NA 95/100 rest of the world 102/100, in US males under 15 exceed females 105/100 – women start outnumbering men around age 40 by 65 women are 58%

In LDCs high maternal death rates cause the figure to be skewed

ELDERLY POPULATION

POPULATION PYRAMIDS IN U.S. CITIES

Fig. 2-16: Population pyramids can vary greatly with different fertility rates (Laredo vs. Honolulu), or among military bases (Unalaska), college towns (Lawrence), and retirement communities (Naples).

RAPID GROWTH IN CAPE VERDE 12 small islands off

coast of west africa Colony of portugal

until 1975 Moved from 1-2 in

1950 Many famines Pop has tripled,

natural increase is 3%

Fig. 2-17: Cape Verde, which entered stage 2 of the demographic transition in about 1950, is experiencing rapid population growth. Its population history reflects the impacts of famines and out-migration.

MODERATE GROWTH IN CHILE Moved from rural to urban Many still prefer large

families Was still stage 1 as of 1900 Most pop increase is from

immigration 1930s move to stage 2 –

medical tech; stage 3 since 1960s –vigourous government family planning, high unemployment rates; govt reversed its policyFig. 2-18: Chile entered stage 2 of the demographic transition in the

1930s, and it entered stage 3 in the 1960s.

LOW GROWTH IN DENMARK Stage 4 Zpg Increasing # of

elderly raises cdr

Fig. 2-19: Denmark has been in stage 4 of the demographic transition since the 1970s, with little population growth since then. Its population pyramid shows increasing numbers of elderly and few children.

CENSUS TAKING IN CHINA Information for pop pyramids is

obtained through census taking

Most countries are in 2 and 3 stage – rapid growth/moderate growth

2 things impacting the model today – tech innovation has diffused throughout the world which drops cdr, cbr continues to increase bc social customs have not changed

19th c change in cdr due to industiral revolution; drop in cdr in other places due to diffusion of this tech