Population structure and control1. What is a census?

2. Why is it difficult to compare census information between countries?

3. Why can census information be unreliable?

4. How can population presented? Name as many ways as you can.

http://www.indexmundi.com/g/g.aspx?v=21&c=sp&l=en

Dependency Ratios A country's population can be divided into three

groups, old dependents, young dependents and economically active.

Old dependents: Anyone over the age of 65. These people are normally retired.

Young dependents: Anyone under the age of 16. These people are normally being cared for at home or are at school.

Economically active: People between the ages of 16 and 65. These people are normally working and pay taxes.

Dependency Ratios Dependency Ratio: the relation between

dependents (old and young) and economically active. The dependency ratio is calculated using the following formula:

N.B: The dependent Population is the sum of old and young dependents.

Examples:1. The UK has a dependency ratio of 0.65 (2004)2. India has a dependency ratio of 0.54 (2012)3. Greece has a dependency ratio of 0.37 (2004)

Factors influencing High Dependency Ratios:

Increasing life expectancy- people are living longer, which means that more children are being born and are also living longer.

Falling death rates- Less deaths due to advances in medical care mean that less elderly are dying of degenerative diseases and infant mortality rates are decreasing.

Rising Birth rates- more children + live to a large age. Immigration of dependents- if young and elderly migrate

into a country, the dependency ratio will rise. Emigration of economically active- If economically active

leave the country, the dependency ratio will rise as the number of economically active decreases.

Ageing dependency RatiosAgeing ratio: The proportion of people over

the age of 65 compared the total population.

dependency ratio: population aged 65+ -15 x100 population aged 15-64

Homework 1. Work out the population dependency rate for Spain? 2. Does Spain have a high or low dependency ratio? Explain your answer

using statistics3. Create a population pyramid for The Gambia – depending on the year you

were given