Population Pyramids

Ch. 19 p. 332

Define Population Pyramid p. 331-336Graphs that show the structure of a population by age & gender

Expanding #1Low life expectancy… HEIGHT of pyramid!

!High death rates … pyramid is narrow along the sides, especially the middle & top.

!High birth rates …BASE of pyramid is wide)….why?

!Generally a lower standard of living!

!In today’s world… UNDERDEVELOPED countries.

Expanding – How do you know?

BASE is WIDER than the middle section

!In other words the YOUNG (<15 yrs) outnumber those in the FERTILITY GROUP (15-39 yrs)

Expanding #2Higher life expectancy …why? (height getter higher)

!High death rate (Narrow tip of pyramid)

!High Birth Rate…(wide base of pyramid)

!Developing nation…because of access to health care!!

!Getting wider & higher!!!)

Stable or Stationary

Higher life expectancy (again getting taller).

!Death rate are also declining (Sides are widening!).

!Birth Rate are declining… (bottom of the pyramid narrowing or shrinking)!!!

!Developed countries… women’s roles, career, education & family choices, etc.!!

Stationary – How do you know?

BASE & the middle section are almost EQUAL

!In other words the YOUNG (<15 yrs) is approximately the SAME as those in the FERTILITY GROUP (15-39 yrs)

Contracting (shrinking)

Higher life expectancy (height of pyramid is high.)

!Death rate are also declining (top widening even more).

!Birth Rate very low (bottom shrinking/narrowing)...why? !Consists of a GRAYING POPULATION (more older people than younger…health care, lifestyle choices etc.)

!Developed countries such as Canada, US, Sweden etc.

Contracting – How do you know?

BASE is MORE NARROW than the middle section

!In other words the YOUNG (<15 yrs) much lower than the FERTILITY GROUP (15-39 yrs)

Another quick look

PRACTICE

Classify each as expanding, stationary or contracting.

!Which would have the lowest standard of living? Why?

!Which would have the highest standard of living? Why?

!Which would resemble Canada? Iceland? Afghanistan?

The answers !!

Stationary Iceland

!!

Expanding Afghanistan Lowest Standard of Living

!!

Contracting Canada Highest Standard of Living

Derive population characteristics from a population pyramid.

Width of the base: birth rate (wide vs. narrow) !

Height: indicates life expectancy !

Symmetry: compares males & females (left side vs. right side)

!Type – determined by comparing the Middle Vs Base (Expanding, Stationary or Contracting?)

Derive population characteristics from a population pyramid.

Shape of sides: indicate death rate (concave vs. convex, wide vs. narrow) !

Bumps in the sides: indicate demographic anomaly...irregularities, events (indentations vs. protrusions) !

Classification; indicates standard of living & level of development etc. (different types)

Compare “population pyramid shape” & standard of living.

Generally speaking stable/contracting populations are characteristic of a high standard of living due to:

Low birth rate due to good family planning, access and affordability of birth control, financial & career planning, education, etc. Low death rate due to good medical care, nutrition, education, sanitation etc., etc.. !

Generally speaking an expanding population is characteristic of a lower standard of living.

High birth rate due to poor access and expense of birth control, lack of education etc. High death rate due to poor medical care, education & nutrition, lack of sanitation etc., etc..

Dependency Ratio

What does dependant mean? Who are the dependants in society? Dependency Ratio: The ratio of dependant people to working people.

!Dependants include:

(0-14 years old) AND (65+ years old) !

Working People include: (15-64 years old )

!The formula is:

DR = (pop. 0-14) + (pop. 65+) X 100 (pop. 15-64)

!The dependency ratio (DR) of a population indicates how many people are dependant upon every 100 workers.

Dependency ratios

The dependency ratio (DR) of a population indicates how many people are dependant upon every 100 workers.

!

The formula is: DR = (pop. 0-14) + (pop. 65+) X 100

(pop. 15-64)

Sample Questions

Sample Questions

Sample Questions

Look for TransitionsLook at the upcoming slides. What

patterns do you see as a population gets older. Canada is becoming a grey pop – what will that mean. China has a shifting population – look at the bumps. Chad is very young and expanding–

what does this mean

Canada

CHAD

CHINA

Which is El Salvador? Which is Finland?

Go to http://www.census.gov/ipc/www/idbpyr.html and create your own population pyramids