Population

¡  1)Conditionsthatattractmigrantsarecalledpullfactors¡  2)Conditionsinthesendingcountrythatcausepeopletomoveawayarecalledpushfactors

¡  3)Peoplewhoareforcedtomovefromtheirhomes,butnotoutsidethebordersoftheircountryarecalledinternallydisplacedpersons(IDPs)

¡  4)Themovementofpeoplefromoneareatoanotherbecauseofchangingenvironmentalconditionsiscalledecologicalmigration

¡  5)Themovementofpeopleagainsttheirwill,oftenduetopersecutionorfearofpersecution,iscalledinvoluntarymigration

Definitions

¡  6)Peoplewholeavetheirhomecountrybecausetheyfearfortheirsafetyarecalledrefugees

¡  7)ThecountrythathasreceivedmorethanonemillionrefugeesfromtheconflictsinbothAfghanistanandIraqisIran

¡  8)Whenconditionsinthehomecountryimprovesothatrefugeesmaysafelyreturnhome,theprocessiscalledvoluntaryrepatriation

¡  9)Whenagovernmentgivesillegalimmigrantslegalstatus,theprocessisknownasanamnesty

¡  10)Migrationneededtooffsetthegrowingproblemofanagingworkforce/decliningpopulationiscalledreplacementmigration

Definitions

¡  Theseare:Voluntaryorinvoluntary?Permanentortemporary?Legalorillegal?Internationalorinternal?

¡  11)Thetwomainwaysthatpeoplebecomeillegalimmigrantsare-enteringacountryillegally¡  -illegallyremaininginthecountryafteravisahasexpiredoranasylumapplicationhasbeendenied

¡  12)ThetworegionsintheworldthatreceivethemostillegalimmigrantsareUnitedStatesandWesternEurope

¡  13)TwoCanadianprovincesthathavehadtheirpopulationsincreasedbecauseofinternalmigrationareAlberta,BritishColumbia

Thevariouscategoriesofmigrationaredeterminedbyfourquestions

Population Pyramids

Hans Rosling •  https://www.ted.com/talks/

hans_rosling_on_global_population_growth/transcript?language=en

PopulationPyramids•  Apopulationpyramidistwoback-to-backbargraphs,oneshowingthenumberofmalesandoneshowingfemalesinaparticularpopulationinfive-yearagegroups(alsocalledcohorts).

•  Agreatdealofinformationaboutthepopulationbrokendownbyageandsexcanbereadfromapopulationpyramid,andthiscanshedlightontheextentofitsdevelopment.– Birthratetrends– Deathratetrends– Numberofeconomicdependents(<15,>65)

PopulationPyramidsThreebasicshapesofpopulationpyramids

.

Population Pyramids – CAN 1961

Depression

Baby Boom

Aging Population

Population Pyramids – CAN 2006

Population Pyramids – US 1990

Population Pyramids – US 2000

Population Pyramids – US 2025

Population Pyramids – US 2050

Population Pyramids – US 2100

PowerofPyramid:SAK

•  Demographers categorize any population they examine into its male and female components by age divisions called cohorts.

•  The most common cohorts are five year intervals.

•  This data is displayed in so-called age-sex structure.

•  Because the age-sex structures of many countries take a triangular or pyramidal shape, this type of graph is called POPULATION PYRAMID.

Reading Population Pyramids Observing different characteristics of the population

pyramid can tell you a lot about the population. •  Width of the base:

–  birth rate varies with the width of the base.  A wide base indicates a high birth rate and a narrow base indicates a low birth rate.

•  Symmetry: –  statistically speaking pyramids should be relatively

symmetrical.  Any asymmetry indicates a difference in the male and female population.  This pyramid shows more females at the 85+ age range which indicates that women are living to older ages than males.

Expansive or expanding •  Expansive or expanding

population pyramids have this classic triangular/pyramid shape. 

•  The wide base of this population pyramid indicates a  high birth rate & the narrow top indicates a high death rate

Expansive or Extending II •  Generally speaking an expanding

population is characteristic of a lower standard of living: – high birth rate due to poor access to birth

control, lack of education etc.; •  high death rate due to poor medical

care & nutrition

Stationary or Stable •  population pyramids

have a 1/2 elipse shape.  •  The base of this

population pyramid is similar in width to the population of the reproductive ages which indicates a  stable population.

Stationary or Stable II •  Generally speaking stable populations

are characteristic of a high standard of living due to: –  low birth rate due to good family planning,

access to birth control, financial planning, education, etc.;

–  low death rate due to good medical care, nutrition, education etc.

Contractive or contracting •  population pyramids

have a narrower base than the reproductive age population. 

•  This indicates a  decreasing population trend. 

•  The low birth rate is indicative of a well developed country

Reading Population Pyramids •  Shape of sides:

–  Concave sides indicate a high death rate and convex sides indicate a low death rate. 

–  If the population pyramid exhibits concave sides it indicates a high death rate.

Descriptions •  Bumps in the sides:

–  Irregularities in the sides indicate a demographic anomaly.  –  The 30 -50 age group in the population pyramid represents

the baby boom.  –  This bump will travel upward as the baby boomers age.

•  Classification: –  Indicates standard of living as described above.

Dependency Ratio u  The working age of people varies.  u  Traditionally people worked until they were 65 years old.  u  The common trend now is for people to retire closer to 55 years

of age.  u  However, for statistic purposes we recognize people between 15

and 65 as the workers of a society.  u  People under 15 and over 65 are considered dependant upon the

working population.  u  The dependency ratio (DR) of a population indicates how many

people are dependant upon every 100 workers. The formula is   

DR = (pop. 0-14) + (pop. 65+)*100         (pop. 15-64)

Test Yourself

1.  What does the vertical axis on the population pyramid represent?

2.  What type of population pyramid is indicative of a lesser developed country?

3.  What does a narrow base to the population pyramid indicate? 4.  What type of population pyramid has a triangular shape? 5.  What type of population pyramid is wider at the reproductive

age than at the pre-reproductive ages. 6.  _?_ are graphs that show the age structure of a population by

age & gender. 7.  What type of population pyramid is depicted below? What

characteristic of this population pyramid indicate its high death rate?

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The Demographic Transition Model

•  Birth and death Rates appear to go through a sequence of predictable changes.

•  Demographers call this pattern of changes

The DEMOGRAPHIC TRANSITION

Stages of the Demographic Transition Stage Birth rate Death Rate Conditions

1 High High Very primitive health and medical conditions: very poor living conditions,a short life expectancy

2 Slowly Decreasing Sharply Decreasing Improving economic,social,and health conditions:still largely agricultural and rural:large families

3 Sharply Decreasing Slowly Decreasing A more urban nation;more manufacturing: improved standard of living and of birth control;women join the labour force;smaller families

4 Low Low Excellent standard of living:good medical and health conditions:a long life expectancy; an older population

Transition 1 •  Both high birth rates and death rates fluctuate in the first stage of

the population model giving a small population growth (shown by the small total population graph). There are many reasons for this:

•  little access to birth control •  many children die in infancy (high infant mortality) so parents tend to

have more children to compensate in the hopes that more will live •  children are needed to work on the land to grow food for the family •  children are regarded as a sign of virility in some cultures •  religious beliefs (e.g. Roman Catholics and Hindus) encourage large

families •  high death rates, especially among children because of disease, famine,

poor diet, poor hygiene, little medical science.

Stage 2 •  Birth rates remain high, but death rates fall rapidly

causing a high population growth (as shown by the total population graph). The reasons for this could be:

•  improvements in medical care - hospitals, medicines, etc.

•  improvements in sanitation and water supply •  quality and quantity of food produced rises •  transport and communications improve the movements

of food and medical supplies •  decrease in infant mortality.

Stage 3 •  Birth rates now fall rapidly while death rates continue to fall.

The total population begins to peak and the population increase slows to a constant. The reasons for this could be:

•  increased access to contraception •  lower infant mortality rate means there is less need to have a

bigger family •  industrialization and mechanization means fewer laborers are

required •  the desire for material possessions takes over the desire for

large families as wealth increases •  equality for women means that they are able to follow a career

path rather than feeling obligated to have a family.

Stage 4 •  Both birth rates and death rates remain

low, fluctuating with 'baby booms' and epidemics of illnesses and disease.

•  This results in a steady population.

Stage 5? •  stage 5 was not originally thought of as part

of the DTM, but some northern countries are now reaching the stage where total population is declining where birth rates have dropped below death rates. One such country is Germany, which has taken in foreign workers to fill jobs. The UK's population is expected to start declining by 2021.

Examples •  Population changes over time and space and the DTM

can show both of these. Examples for both of these are shown below. Firstly, examples of countries that can be classed as exhibiting the population traits now, are shown as an example of how population can change over SPACE. Secondly, the dates the UK passed through each stage are indicated as an example of how population in one country can change over TIME.

•  Stage 1 Ethiopia / Bangladesh UK: pre-1780

•  Stage 2 Sri Lanka / Brazil UK: 1780 - 1880

•  Stage 3 Uruguay / China UK: 1880 - 1940 Stage 4 Canada / Japan UK: post-1940

Three Patterns of Population Change

Comparing with the PPM •  Each of the stages of the Demographic

Transition Model (DTM) can be directly compared to the stages of the Population Pyramid Model.

•  The chart below indicates ways in which the DTM and PPM differ or are similar in their structure.

Comparing with the PPM •  Demographic Transition Model •  drawn as a line graph •  doesn't show male and female populations •  shows total population as a separate line •  gives details of countries in stages •  shows the relationship between birth and

death rates and how these affect total population obviously (using the line graphs)

•  only one diagram necessary to show all stages

•  Population Pyramid Model •  drawn as a bar graph •  shows male and female population

proportions •  total population is shown as the total area

of the graph •  shows greater detail about the

populations at each stage (amount in each age and gender at any one time)

•  shows direct relationship between birth and death rates and how these affect total population indirectly (through the shape of the diagrams)

•  four diagrams necessary to show all stages