TERMS & DEFINITIONS
BIRTH RATE: no. live births per 1000 per year.
DEATH RATE: no. deaths per 1000 per year.
FERTILITY RATE (FECUNDITY): average no. children a women will have aged 15-44 (reproductive age)
INFANT MORTALITY RATE: no. of children that die before their 1st birthday.
LIFE EXPECTANCY (LONGEVITY): average no. of yrs a person can expect to live.
MIGRATION RATE: difference between no. of immigrants & no. of emmigrants per 100,000 of a population per yr.
POPULATION DENSITY: no. of people per square km.
Total pop. of area divided by size of area (in km2)
DEMOGRAPHIC TRANSITION MODEL.
STAGE ONE: HIGH BR, HIGH DR.
- BR & DR fluctuate at a high level - pop. remains stable, but low.
- no countries at Stage 1, but some tribes in Brazilian rainforest.
- BR high: no birth control/family planning, poor education, high infant mortality rate - people have more children to replace dead.
- DR high & LE low: poor health care, sanitation, diet, starvation & disease.
STAGE TWO: HIGH BR, FALLING DR.
- e.g. Nepal & Afghanistan.
- BR high still: little birth control/family planning, poor education & labour: whole family have to work = people have larger family, need more money & more food.
- DR falling, LE increasing: better health care, sanitation, diet.
STAGE THREE: BR FALLING A LOT, DR FALLING SLIGHTLY
- e.g. Egypt.
- BR falling: increased birth control/family planning & education improvements, as economy moves towards manufacturing: less children needed to work & more employed women.
- some countries introduce Govt. pop. policies to try to reduce BR.
STAGE FOUR: BR FALLING, DR FALLING.
- e.g. most developed countries: USA & Europe.
- BR & DR fluctuate at low level - pop. remains stable but high.
- BR remains low as access & demand for luxuries e.g. holidays/material possessions increases, leaving less ££ for children.
- also, there are less advantages to having children: they're not needed to work.
STAGE FIVE: DR IS HIGHER THAN FALLING BR
- e.g. Japan.
- BR begins to decline whilst DR remains stable.
- pop begins to decrease.
- declining BR: children expensive to raise; many have dependent elderly relatives therefore lots choose not to have children.
- DR remains stable: more elderly people = more deaths (of old age), despite medical advances.
DTM = USEFUL, BUT HAS LIMITATIONS.
- gives good generalised picture of how population can change.
- easy to compare a country with the DTM.
e.g. if you know how a country's BR & DR have changed, you can analyse what stage its in.
you can then forecase how its population may change in the future.
you can help Govts. decide on policies e.g. 1 child policies, immigration laws.
- original data used to create DTM was from more developed, richer countries e.g. Japan, Usa.
therefore DTM may not be a valid model worldwide.
- original DTM didn't have Stage 5 - its been added since some countries progresses out of 4.
- DTM doesn't take things e.g. education, womens' roles into account seperately & these affect BR e.g. increased higher education = people delaying children.
- population in countries with different customs may change in different ways e.g. Catholic Church condemns contraception.
- extreme poverty & law development levels may cause a lack of pop. growth & prevent many LEDCs passing through all stages.
- DTM can't predict exactly when countries will reach each stage, or how long each stage will last.
- DTM doesn't consider migration: international migration can have large effect on pop. change.
Other factors can affect pop. so a country no longer fits the DTM...
- Pop. control policies e.g. France, China.
- high. pop growth/decline levels have forced some Govts. to introduce policies discouraging/encouraging large families.
- e.g. pop. growth in France = very low: Govt. introduced things like subsided childcare to encourage large families.
- e.g. China - Govt. tried to reduce BR using 1 child policy.
- Infectious diseases e.g. HIV/AIDS, Malaria.
- some countries have high levels of infectious disease, keeping DR high, reducing pop. or stalling pop. growth.
- e.g. Nigeria & Botswana have v. high HIV/AIDS rates = high DR.
- Civil War e.g. Rwanda, Sierra Leone, ongoing in Sudan.
- war = high DR, low BR, espec. if lots of men & women of reproductive age are killed/involved.
- civil war often leads to emigration which leads to declining pop. as people flee.
- e.g. thousands died during S. Leone war (1991-2002) & thousands more fled to neighbouring countries.