Population

Dependency Ratio

• A measure showing the number of dependents (aged 0-14 and over the age of 65) to the total population (aged 15-64).

Total populationDependency ratio= -----------------------------

Number of people in work

Calculate

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Causes of population change

Three ways of increase in population:

1. Increase in number of

birth.

2. Decrease in number of

death.

3. Immigration >Emigration

Natural rate of increase

The natural rate of

increase in a population is the difference between the birth rate and death rate.

Birth rate - Death rate.

Birth rate

• The average number of children born in a country each year compared to the total population is the birth rate.

• It is expressed as the number of births for every 1000 people in the population.

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Why difference in birth rate?

Living standards

• Improvement in quality of life reduce the death of babies.

• But in less developed countries, still babies die.• They want large families to support income.

Contraception

• Increased use of contraception has reduced birth rates in developed countries.

• But due to lack of education, birth rate is still high in developing countries.

Custom and religion

• Some religious beliefs does not allow people to use contraception or abortion.

Female employment

• In developed countries, female employment is more.

• They do not want to break their careers to bring up children.

• Also children causes drain of income.

Marriages

• Late marriages reduces the chances of baby births.

Death rate

• The number of people die each year compared to every 1000 people is the death rate.

Why difference in death rate?

• Living standards

• Medical advances

Migration

• Net migration measures the difference between immigration and emigration to and from a country.

Structure of population

• Structure is based on:• Age distribution• Sex distribution• Geographical distribution• Occupational distribution

Age distribution

• It refers to the number of people, or percentage of population in each age group.

• Falling birth and death rate leads to an increase in average year of population.

Population pyramid

• It is a pyramid-shaped diagram illustrating the age distribution of a population:

• The youngest are represented by a rectangle at the base, the oldest by one at the apex

Geographical distribution

• It refers to where people live.• Almost 90% of the world population live in

less developed countries.• Most densely populated place in the world is

Monaco in Europe (23000 people per square km)

Ubanisation

• Around half of the world’s population lives in urban areas.

• Concerns:

Increased consumption of scarce natural resources such as trees, open space and water…Pollution…..

Population Density Map of India 2001

Occupational distribution

• This refers to the types of job people do.

• In 2005, the total working population was 3 billion

3billion

40% in agriculture

21% in secondary

39% in service