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
Births
A specific pattern of population growth has occurred in many developed nations
during the past 60 years.
Baby Boom
Baby Echo
Generation Y
Generation X
1945
1965
1985
2005
2025
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