GEO 206 Lecture Notes - Lecture 4: Dependency Ratio, Population Ageing, Epidemiological Transition
LECTURE #4: POPULATION
Distribution
Population by Latitude
● "Roughly 88% of the world's population lives in the northern hemisphere, and about half
the world's population lives north of 22 degrees North.
● Taking the northern and southern hemispheres together, on average the world's
population lives 24 degrees from the equator."
● Dividing the world between North and South
Population by Longitude
● Dividing the world between West and East
Population by Country
● scale of the state to determine space
● can be defined by population
Population by Continent
Population by Area: Density
● Crude Density: Total number of people divided by total land area
● We can look internally within a country but we can also see groupings or clusters of
population concentration in the world
○ Clusters: East Asia, South Asia, Europe
Canada's Population Distribution 2006
● factors determining population distribution: resources, accessibility in terms of historical,
cold, mountains
● there is an intensity in west of Canada because of resource development
○ Oil in Alberta in 1902, then Turner Valley
○ begin develop of oil sands but not until 190s and 1990s was the price high
enough and the technology good enough
Factors Affecting Distribution
● Environmental
● Historical
● Socio-economic
● Technology
● Political
Structure
● the structure of the population (usually done by country) can tell a lot about the past,
present, and future of population issues
Age Cohorts
● Youth
○ under 15 yrs of age
○ planning for education
● Middle
○ 15 to 64 years of age
○ workforce, housing
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● Old-Age
○ 65 years of age and over
○ Health, pensions
● all of these groups have different needs
Dependency Ratio
● Youth + Old-Age/Middle
● The total demographic dependency ratio is the ratio of the combined youth population (0
to 19 years) and senior population (65 or older) to the working-age population (20 to 64
years). It is expressed as the number of "dependents" for every 100 "workers":
○ youth (ages 0 to 19) + seniors (age 65 or older) per 100 workers (aged 20 to 64)
● The youth demographic dependency ratio is the ratio of the youth population to the
working-age population
● The senior demographic dependency ratio is the ratio of seniors to the working-age
population
● The demographic dependency ratio is based on age rather than employment status. It
does not account for young people or seniors who are working, nor for working-age
people who are unemployed or not in the labour force. It merely reflects population age
structure and is not meant to diminish the contributions made by people classified as
"dependents".
● Changes in demographic dependency ratios highlight changes in the age composition of
the population.
Canada's Age Cohorts 2010
● Stability of the total demographic dependency ratio throughout the 1908s and the 1990s
was attributable to a decreasing youth demographic dependency ratio that was offset by
an increasing senior demographic dependency ratio
● The decreasing youth demographic dependency ratio and the increasing senior
demographic dependency ratio show that more people are moving out of the working
age range than into it.
● The shrinking percentage of young people means that in the future, the number of
workers may be insufficient to finance the pensions of retirees
● More than 7 in 10 Canadian Pre-Retirees Expect to Work Past Age 65
Canada's Population Pyramid to Pillar
● Baby boom: "increased number of births in the two decades after WWII.
● One way of summarizing the age structure is through population pyramids
○ separated by gender - males on one side; females on the other
○ This can tell a lot about past populations and what is going to happen in the
future
Canada's Generations
● Baby boomers: born 1946-65
● Generation X: born ca. 1967-79 (baby bust)
● Generation Y: born ca. 1980-95
The Aging World
● "population ageing is one of the most significant trends of the 21st century
● The whole world is aging
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