Population

• http://www.youtube.com/watch?v=4BbkQiQyaYc

What ways can we look at population?• Cultural background• Age• Sex• Geographic location• Native status• Diseases

Why study populations?• The reason we study various populations

is so we can answer questions like these:

Why are more schools closing than opening? Why will you likely have to work more years than your parents before retiring? Why are old rock-and-roll groups, such as the Rolling Stones, still so popular?

The percentage of one of these two age groups is increasing. Which one?

Our 2 Ways• We will look at population in 2 ways:

• Age/Gender &

• Geographic

Population Pyramids

Age/Gender

Population Pyramids

• A method that uses graphs to make statistical data easier to understand

• A graph that depicts population distribution by age and sex• Females on the right

• … and males on the left

• Both sides show the percentages of people in each age group.

The Study of Populations• Putting the two sides together can allow you to easily

compare a country’s population for different years (or to compare different countries).

How to arrange the graphs

Different Ages/Roles Demongraphers have identified three

important stages of our lives in which we have different roles Stage 1: Children (up to age 14) Stage 2: Working Adults (ages 15-64) Stage 3: Older Adults (age 65 and over)

This model assumes that children and older adults are not working and must be supported by the working population

Dependency Load• the part of the population that needs to be supported. It is

made up of two components: the 0–14 age group and the 65+ age group.

Dependency Load• The portion of the population that is not in

the work force

• What is the effect of a high dependency load? Great deal of pressure on the society to

provide education, housing, health care, old-age homes and other needs

The Study of Populations• What has happened to the dependency

load between 1956 and 2004?• What is the significance of this change?

The Study of Populations• Populations within countries change over

time in a predictable manner as they become more industrialized.

• This is called the Demographic Transition Model as was created by Thomas Malthus.

The Study of Populations• What is happening at each stage?• Why is it happening?

The Study of Populations• A specific pattern of population growth has

occurred in many developed nations during the past 60 years.

1945 1965 1985 2005 2025

Birt

hs Baby Boom

Generation X

Baby Echo

Generation Y

Making a Population Pyramid

Rules Males on the left, females on the right Age is grouped in cohorts (sets of numbers) ex. 0-4, 5-9

and numbers do not overlap Age increases towards the top (oldest at top) The scale for males must be the same as the scale for

females The scale at the top of the pyramid can show either

population or percentage Label all axes (including units of measure) Include a title complete with date of pyramid and location Use different colour for males and females

Lets make the pyramid