Population Dynamics

World Population Growth

Growth of world population

World population in 1804 stood at 1 billion and has shot up to roughly 7 billion in 2012. The main reason for this is the fall in the death rate. More recently, there has been a fall in the birth rate which means that the rate at which our population grows is predicted to slow down, but nobody knows when it is going to reach zero. Some estimates are that it the rate of population growth will hit zero by 2020, while others think the global population will reach 10 billion by 2100.
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The demographic transition model

The demographic transition model is a model which shows population change over time. It takes into account the birth rate and death rate and how this affects the overall population and the country.

There are 5 different stages of the demographic transition model.

Stage 1
  • High birth rates
    • no birth control
    • children seen as an asset who can work which leads to large families.
  • High death rates
    • frequent famines
    • outbreaks of disease, e.g.: plague, typhoid.
Stage 2
  • High birth rates
  • Falling death rates
    • improved hygiene, health care, nutrition
    • safer drinking water 
    • better sewage disposal
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Stage 3
  • Falling birth rates
    • birth control
    • less children dying
    • People beginning to want smaller families for economic reasons.
  • Falling death rates
Stage 4
  • Low birth rates
    • women delaying having children
    • birth control
  • Low death rates
    • continual improvement in health care
Stage 5
  • Slightly rising death rate
    • many old people
  • Low birth rate
    • fewer young people so fewer having families

Population pyramids

Not all countries will be at the same stage of development, which means they will also have different population structures. These population structure can be shown using population pyramids.

Population Pyramids...
  • Show the number or percentage of different age groups for each gender in the population.
  • Can be used to determine what stage a country is in the Demographic Transition Model.
  • Show changes in birth rate and death rate
    • the bottom of the pyramid narrows as the birth rate lowers
    • the top gets higher and wider as life expectancy increases
  • Show short-term factors that can impact on population, e.g.: war leading to a higher death rate especially in young adult males.
  • Can forecast population totals and growth rates to help future planning.
 Angola Population Pyramid - 2014
Central Intelligence Agency
Wide base = higher birth rate
Narrow top = shorter life expectancy and fewer people living to an older age
Youthful population
UK Population Pyramid - 2014
Central Intelligence Agency
- Narrow base = low birth rate
- Similar numbers in each age group = low death rate
- Wide top = long life expectancy
- Ageing population
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Population issues

Both youthful populations (high proportion of people aged under 16) and ageing populations (high proportion of people over 65) have their individual challenges that the government and people have to deal with. This is because youthful and ageing populations are dependent on the working population which has to support these dependants financially and socially.
An ageing population means more money is needed for:
  • state pensions
  • social provisions such as home help, meals on wheels, suitable housing
  • medical provisions, e.g.: care homes, increased need for hospital beds and professionals to cope with diseases of the elderly, such as dementia.
A youthful population means more money is needed for:
  • social provisions such as nurseries, schools, play grounds, child-specific benefits, e.g.: maternity and paternity leave
  • medical provisions, e.g.: maternity units in hospitals, paediatric medical facilities, etc.

Problems for the elderly in the UK
  • Difficulty of getting around if no public transport
  • Living alone when partners die
  • High cost of residential homes
  • Having to sell homes to pay for care
  • Fear of crime
  • Long waits for hospitals appointments

Managing Populations

The population of a country should be sustainable. It should not harm the environment nor the quality of life of the people.

Overpopulation - When a country has more people than can be supported by its resurces
Underpopulation - When a country has more resources than people


Problems of overpopulation

Problems of underpopulation

Resources Not enough resources may lead to malnutrition and starvation Not enough people to exploit the resources 
Services Shortages of housing and educational and medical services Not enough people to pay taxes for services 
Employment Unemployment - poverty for individuals and strain on benefits Underemployment/Skills shortages negatively affect economy
Other issues Overcrowding leading to poor living conditions, especially in urban areas Often an ageing population - low fertility. 

How can populations be made sustainable

  • Make sure there are not too many and not too few people.
  • Making sure there are enough people of working age to support the rest of the population
  • Managing resources so as not to use too many
  • Recycling resources as much as possible
  • Looking after the environment

Pro-natal and anti-natal policies

One way in which governments can manage its population is by trying to increase or decrease the birth rate. 

Pro-natalist policy - A policy to encourage people to have children
Anti-natalist policy - A policy to discourage people from having children

Anti-natalist case study - China

  • A huge population growth in the mid-20th century led to a series of famines
  • In 1979, China established the "One Child Policy" which encourages people to have one child only. It would also penalise people who decided to have more than one child.
  • How it works...
    • Incentives given for having just one child:
      • cash bonuses
      • longer maternity leave
      • better childcare
      • preferential access to housing
    • Young people persuaded to delay marriage
    • Pressure for abortion of 'unauthorised' pregnancies.
    • Easy access to contraception and encouragement of post-pregnancy sterilisation
    • 'Forced' sterilisation of couples who have more than one child.
  • Overall, the One Child Policy has been successful and the birth rate and population growth rate have both fallen. However, in rural areas, the policy had not been so rigorously forced and therefore wasn't so successful
  • The policy has been relaxed in some regions since 1996.

Pro-natalist case study - Singapore

  • Singapore had introduced a policy in the 1960s to help reduce its population, which was very successful, so successful it led to population decline and an ageing population. This meant that it now had to introduce a pro-natalist policy to help increase the birth rate and population.
  • The current policy is "Have three or more - if you can afford it". It offers incentives for couples who decide to have lots of children, especially those who are well-educated (and therefore higher earners).
  • How it works...
    • Incentives for having more than two children:
      • tax rebates
      • cheap nurseries
      • preferential access to the best school
      • spacious apartments
    • Counselling offered to discourage abortions and sterilisation
    • Works alongside immigration policy that encourages young graduates (of child-bearing age) to immigrate to Singapore.
  • The policy has been successful and has resulted in an increase in birth rate and helped increased population.

Migration policies

Migration - the flow of people in and out of a country.
Governments may want to manage migration to control their country's populations.

There are three different migration policies...
  • Open door - This type of policy allows anyone to come to live in a country. The country will often run campaigns abroad, usually targeting specific groups, to try and encourage people to go and live in that country. For example, there is an open-door policy for migration between EU countries.
  • Quotas - This restricts the number of people allowed into a country per year. The country may decide on different things to restrict, e.g.: total number allowed, a total number from a particular area or a particular type of person.
  • Skills Test - Potential migrants have to pass a 'skills test'. This ensures that all the migrants a country receives are skilled and qualified. It may also involve a points system where you have to have skills in certain areas to get enough points to qualify to be admitted.
Why encourage immigration Tensions
  • Can help address underpopulation
  • Helps address labour shortages - immigrants often do jobs that native people would rather not do
  • Meets specific skills shortages: doctors, teachers, engineers
  • Working-aged immigrants pay taxes which help pay for services
  • Immigrants add to a country's talent and culture.
  • Pressures on housing, health care and education caused by immigration
  • Fear by native population that immigrants are 'taking their jobs'.
  • Discrimination / abuse of immigrants
  • Perception that immigrants take advantage of state benefits
  • Can alienate 'native' population
  • Quotas or skills tests may cause problems for people who want to bring family to live with them.