Population Dynamics

World Population Growth

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.

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.

The demographic transition model

There are 5 different stages of the demographic transition model.

Stage 1

Stage 2

Stage 3

Stage 4

Stage 5

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:

Angola Population Pyramid - 2014

Angola Population Pyramid

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

UK Population Pyramid

Central Intelligence Agency


  • Narrow base = low birth rate
  • Similar numbers in each age group = low death rate
  • Wide top = long life expectancy
  • Ageing population

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: A youthful population means more money is needed for:
state pensions social provisions such as nurseries, schools, play grounds, child-specific benefits, e.g.: maternity and paternity leave
social provisions such as home help, meals on wheels, suitable housing medical provisions, e.g.: maternity units in hospitals, paediatric medical facilities, etc.
medical provisions, e.g.: care homes, increased need for hospital beds and professionals to cope with diseases of the elderly, such as dementia.

Problems for the elderly in the UK

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 resources
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

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
Pro-natalist policy A policy to discourage people from having children

Anti-natalist case study - China

Pro-natalist case study - Singapore

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 Pressures on housing, health care and education caused by immigration
Helps address labour shortages - immigrants often do jobs that native people would rather not do Fear by native population that immigrants are 'taking their jobs'.
Meets specific skills shortages: doctors, teachers, engineers Discrimination / abuse of immigrants
Working-aged immigrants pay taxes which help pay for services Perception that immigrants take advantage of state benefits
Immigrants add to a country's talent and culture. Can alienate 'native' population
Quotas or skills tests may cause problems for people who want to bring family to live with them.