Chapter 2, Key Issue 3 - Demographic Transition

January 5, 2018 | Author: Anonymous | Category: Science, Health Science, Geriatrics
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VARIATIONS IN POPULATION GROWTH DEMOGRAPHIC TRANSITION 

The Demographic Transition  



1. Low growth 2. High growth

– 3. Moderate 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 1) Most of our time on Earth 2) High birth and high death rates NIR is around 0 with population of world around ½ million 3) Food is unpredictable 4) Despite beginning of human settlement, war and disease balance out high birth rates (families depend on children for farming) Low

Growth

Present Day: No countries here

Low Growth 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

1) Industrial Revolution in England and North America (1750-1800) 2) High Birth and decreasing death rates 3) 10x faster growth 4) Stabilization of food supply, improvement of sanitation techniques, and creation of wealth through technology and invention

High Growth

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

Moderate Growth

1) CBR drops, but still is higher than CDR; - CDR continues to decline, but at a slower rate 2) 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•Stage 5? Europe and North America, most of Asia •High CDR and and Latin America by end of 20th century irreversible population decline

1) Most of our time on Earth 2) High birth and high death rates NIR is around 0 with population of world around ½ million

3) Food is unpredictable 4) Despite beginning of human settlement, war and disease balance out high birth rates (families depend on children for farming) Present Day: No countries here

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1) Industrial Revolution in England and North America (1750-1800) 2) High Birth and decreasing death rates 3) 10x faster growth 4) 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.

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1) CBR drops, but still is higher than CDR; - CDR continues to decline, but at a slower rate 2) 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

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1) 2) 3) 4)

CBR declines to the point where it equal CDR NIR approaches zero (Zero Population Growth or ZPG) TFR falls beneath the 2.1 replacement rate Women enter the workforce, more access to birth control methods, more leisure/entertainment time

Present Day: Much of Europe, Russia as example

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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 stage

Fig. 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 Fig. 2-17: Cape Verde, which entered stage 2 of the demographic transition in about is 3%history 1950, is experiencing rapid populationincrease growth. Its population 

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 policy

Fig. 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

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