Population

Definitions

• Birth rate: the number of live births per 1000 people, per year

• Death rate: the number of deaths per 1000 people, per year

• Fertility rate: the average number of children a woman will have between the ages of 15 and 44 (reproductive age)

• Infant mortality rate: the number of children of children (out of every 1000 born alive) who die before their first birthday

Definitions

• Life expectancy (longevity): the average age (in years) a person can expect to live

• Migration rate: the difference between the number of people who migrate in (immigrants) and the number of people who migrate out (emigrants) per 100,000 of the population, per year – the movement of people between or within countries

• Population density: The number of people per square km (km²)- the total population of an area divided by the size of the area (in km²)

Changes in population over time

Natural ChangeThe change in population (increase or decrease) because of the difference between birth rate and death rate (not including changes due to migration)E.g. when birth rate>death rate, the population will grown naturally (if migration rate is zero)When death rate>birth rate, the population will fall (unless enough people migrate in)Zero growth rateThe population is neither increasing nor decreasing (e.g.birth rate=death rate)

The Demographic Transition Modelshows how the population of a country changes over time through five stages-

the model shows changes in birth rate, death rate and total population

As countries develop they move through the stages of the DTM

• Stage 1- high birth rate and high death rateBirth rate and death rate fluctuate at a high level- the population remains stable but lowSome tribes in the rainforests of Brazil are in this stage1. Birth rate is high because there’s no birth control or

family planning and education is poor2. It’s also high because there’s high infant mortality, so

people have more children to replace those who’ve died3. Death rate is high and life expectancy is low because

there’s poor healthcare , sanitation and diet- leading to disease and starvation

Birth rate- around 35/1000 Death rate- around 35/1000

• Stage 2- high birth rate, death rate fallsDeath rate falls, but birth rate remains high- the population increases rapidlyCountries like Napal and Afghanistan are in stage 21. Birth rate is still high as there’s still little birth control or

family planning and education is poor2. Birth rate also stays high for labour reasons- family

members (including children) all have to work, e.g. on farms. A larger family can tend to a larger farm, helping to bring in more food and money

3. Death rate falls and life expectancy increases due to improved health care, sanitation and diet

Birth rate- around 35/1000 Death rate- falls to around 15/1000

• Stage 3- birth rate falls a lot and death rate falls slightly

Birth rate declines rapidly, while death rate falls slowly- the population increases at a slower rate.

Countries like Egypt are in Stage 3

1. Birth rate decreases due to the increased use of birth control and family planning, and improvements in education

2. The birth rate also drops as the economy moves towards manufacturing-fewer children are needed to work on farms, so having a larger family isn’t as advantageous as it once was

3. Birth rate falls further still as more women work rather than stay at home to have children

4. Some countries introduce government population policies to try to reduce the birth rate

Birth rate- falls to around 13/1000 Death rate- falls to around 10/10000

• Stage 4- low birth rate and low death rateBirth rate and death rate fluctuate at a low level- the population remains stable but highMost developed countries e.g. most of Europe and the USA, are in Stage 4Birth rate stays low because increased access and demand for luxuries like holidays and material possessions means there’s less money available for having childrenAlso, there are fewer advantages to having children, e.g. they’re not needed to work for the family

Birth rate- falls to around 10/1000 Death rate- around 10/1000

• Stage 5- birth rate drops below death rateBirth rate begins to decline further while death rate remains stable- the population begins to decrease. Some highly developed countries, e.g. Japan are in Stage 51. The birth rate decreases because children are

expensive to raise and many people have dependent elderly relatives, so lots of people choose not to have children

2. Death rate remains steady as there are more elderly people so more people die despite advances in health care

Birth rate< Death rate