Population Dynamics

The world population is growing at an alarming rate, in 2008 at least another 68 million people were added to the global total of 6.6 billion.
The rate of growth has begun to slow down since 2000 but exponential growth has been occurring - this is the amount of time taken for the population to double, in 1804 it had taken 300 years, in 1999 the doubling time had fallen to 39 years. There are two ways that population can change - through natural change (births and deaths) and migration change (immigrants and out migrants).

Population has been increasing many due to the decline in death rates and infant mortality rates:
Development of modern medicines means that more people are being cured of diseases that would've killed them in the past,
Introduction of vaccination and immunisation programmes,
Cleaner drinking water and better sewage disposal - less spread of disease,
Better healthcare,
More hygiene,
Better diets - '5 a day' promoted

In Yemen (developing), the population is increasing because:
Women marry very young and have a large number of children (6.7),
Increased life expectancy partly due to improved child vaccinations,
High birth rate as the Islamic religion is against birth control.

In some countries the population has declined, this could be due to conflict or diseases such as AIDS/HIV.

Birth rates are high in some countries because:
Children are seen as an economic benefit in some developing countries because they help with the agriculture.
Some religions are against birth control,
Culture to marry young so women are more likely to have more children. 

In Russia, the population is declining due to:
Falling life expectancy caused by industrial disease and alcoholism,
Outward migration of younger fertile men and women,
A low fertility rate of 1.2 children per woman,
Birth rates are declining because:
Women have access to birth control methods,
They may choose to have few children to reduce a chance of economic stress,
More women in education who may choose to have a career before children.

Stage 1: High fluctuation due to no birth control and high infant mortality. High death rate due to disease and famine.
Stage 2: Early expanding due to high birth rate, falling death rates due to improved health care and nutrition.
Stage 3: Late expanding due to falling birth rates due to birth control and wanting smaller families and falling death rates.
Stage 4: Low fluctuating due to low birth and death rates due to working women delaying age to start their family.
Stage 5: Decline because the death rate is higher than the birth rate due to a 'grey population'. 

Population pyramids can also be used to work out the dependancy ratio (a relationship between those who are and aren't working in an area).

Dependency ration = % under 15 + % over 65
   % between 15 and 64 

A broad shape at the top shows a high proportion of people living longer.
The higher the pyramid, the longer people live.
Differences between male and females can be picked out.
Indents show higher death rates than normal because of a war, famine, disease epidemic or through people emigrating.
Bulges show either a period of immigration or a baby boom years before.
A wide base shows a high birth rate.
A narrow base shows a low birth rate.

A youthful population is when there is a high percentage of the population under the age of 15, the benefits are:
- Provides a steady supply of workers and can encourage economies to grow.
- Children provide security and support for old age.
- Children are a valuable source of income for a family as they can work on the land from quite a young age. As children get older they may be able to earn money in other ways. For example, selling snacks to tourists on the beach in a holiday resort.
- As children get older they can help to care for younger children in the family.

Problems:
- Pressures on housing leads to people living in slums (common around big cities)
- Pressure on schooling - illiterate population,
- Pressure on food supplies
- Pressure on health services,
- Rapidly growing population will need housing and employment,
- More difficult for women to work as they have to spend time caring for a large number of children, so they are not earning an income.

A Grey population is when the country has a large number of people over the age of 65. Benefits include:
- More elderly people in MEDC's have money to spend which helps the local economy.
- They can support their grown up children as they raise their young families
- They undertake many worthwhile tasks, many of them voluntary.

Problems:
- Old people cost a lot to support and taxes may rise to pay for extra health and care,
- Shortage of retirement homes and hospital care for the elderly - more will have to be built,
- They may require specially built houses/serviced flats,
- An increase in the cost of pensions because people are living longer so need pensions for longer,
- Shortages of labour,
- Provision of leisure activities for the elderly.
Solutions such as increasing tax, raising retirement age and abolishing state pensions will not prove popular.

20.8% of population ages 65+; 26.8 million pensioners, Birth rate below replacement levels.

Causes:
People living longer due to a healthy diet and high GDP (Average life expectancy for men is 79 and 85 for women),
Birth rate declining due to increased age for first child (2009 average age for first child was 29),

Effects:
Increase cost of pensions as fewer workers,
Government trying to raise retirement age from 60 to 65,
Increase in numbers of nursing homes,
Increase in cost of medical care

31% of the population is under 15, population grew 50 million in 40 years, average age is 26.

Causes:
Low death rate at 5 per 1000 due to vaccinations and doctors,
Falling birth rate but large percentage of young people,
It will take 50 years for Mexico to loose it's youthful population.

Effects:
Increased need for schools,
Young people unable to find work so emigrate to USA,
Growing manufacturing industry,
Strongly Catholic but abortion has been legalised to reduce number of children.

Countries often need to manage their population to gain an optimum population where resources and population are equally balanced, this will make the country sustainable. Governments often step in to manage their populations so that they don't become overpopulated.

Introduced in 1970's - couples not allowed to have more than one child. Couples with one child were given benefits such as cash bonuses, better childcare and improved housing, unauthorised pregnancies pressured to have abortions.

Why?
High growth rate of population - this causes pressure on land and food supplies due to an already large population, total population grown from 996 million in 1980 to 1,320 million today.

Effects - Birth rate fell from 34 per 1000 in 1970 to 13 per 1000 in 2008,
Annual population growth rate fell from 2.4% to 0.6%,
Chinese traditions prefer sons - sex selective abortions occurred,
Shortage of women at marrying age.

Introduced 'mother's salary' where women were paid to have children, 15 months fully paid maternity leave.

Why?
Estonia became independent from Russia in 1992,
Falling population due to the fertility rate declining from 2.2 in 1988 to 1.4 1998,
People planning fewer children due to increased poverty, single lifestyles and young people migrating overseas.

Effects - By 2006, fertility rate rose to 1.5 (still below replacement level).

Open Door - Act of Parliament giving all Common Wealth (ex-colonial) citizens free entry to the UK. This met the shortage of unskilled and semi-skilled labour and helped with the reconstruction of the country post war, public money was spent on meeting the needs of the immigrants which lead to a recession in the 1970's and increased unemployment.

Point based system - you must gain a certain amount of points to be allowed into the country bases on a tier system. Tier one has highly skilled workers such as scientists down to Tier five who are temporary workers such as musicians in a concert. Highly skilled workers are more likely to be let into the country as they will contribute more to society.

The UK immigration of ethnic groups lead to conflict as there was hostility towards them. These ethnic groups banded together into particular areas to reduce the risk of being victimised. The UK government stepped in and stated all citizens regardless of ethnicity should enjoy equal opportunities. Today it is much more harmonious as people have begun to realise the positives of having them; they add to the countries skill base and culture.

Host advantages include - meets need of shortage of unskilled and semi-skilled labour, helped reconstruct UK after the war, increases culture, immigrants contribute to the economy through paying taxes, immigrants often take the low pay jobs, less than 5% claim any sort of state benefit.
Host disadvantages include - public money spent on immigrants e.g. housing and healthcare, during the 1970's recession the immigrants added to the unemployment numbers, hostility increased towards the immigrants.

Source advantages include - immigrants send money/remittances home to their families, less pressure on resources and jobs in places like Poland, immigrants bring skills back to their home country.
Source disadvantages include - loss of working population from source country, decline in birth rate as most immigrants are young men.