Demography: It’s All About People

1. Demography: It’s All About People

2. Demography is the study of populations. It helps answer questions such as • 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?

3. This chapter shows you • how to compare the populations of different countries • how to examine changes in population structure • how to measure population change

4. World Population Growth Since 1 CE

5. How do we compare countries that have populations of different sizes? Use RATES not NUMBERS!

6. Look at the number of births for these three countries. • Canada: 330 000 babies born in 2003 • Russia: 1 458 000 babies born in 2003 • Togo: 191 000 babies born in 2003

7. To calculate each country’s birth rate, divide the number of births in one year by the population, and multiply the result by 1000. The answers are…

8. Birth Rate • Canada (330 000/32 207 000)  1000 = 10 • Russia (1 458 000/144 526 000)  1000 = 10 • Togo (191 000/5 429 000)  1000 = 35

9. In a similar fashion, rates can be calculated for • number of deaths • number of immigrants • number of emigrants

10. Rates can also be combined in the following manner: • natural increase rate = birth rate – death rate • net migration rate = immigration rate – emigration rate

11. Population Growth Rate • A country’s population growth rate = natural increase rate + net migration rate.

12. Canada’s Population Growth Rate

13. The rate at which a country’s population grows or declines has an enormous influence on people’s lives. Why do you think this is so?

14. Comparing Population Growth Rates • These population growth rates may not seem very different: • Canada 0.8% • Russia – 0.4% • Togo 2.4% • But we need to consider the impact of “compounding.”

15. The Power of Compounding • To help pay for your future education costs, your parents offer you two choices. For 30 days, you can receive one of the following: • Which one would you chose: Fig. A or Fig. B? • Fig. B 1 cent + 2 cents + 4 cents + 8 cents … • Fig. A $1000 + $1000 + $1000 + $1000 …

16. If you selected Fig. B, you would have a lot more money for your education. Why? Because growth occurs on top of the growth that has already taken place. • Fig. A $30 000 • Fig. B $10 737 418.23

17. Here is the impact of compounding on the populations of Canada, Russia, and Togo for the next 100 years.

18. Doubling Time • Doubling time is the time it takes a population to double at its current growth rate. • You could calculate doubling time with fancy mathematics. • Or, you could estimate the time by…

19. …using the Rule of 70, which states that doubling time = 70 divided by the population growth rate. • Canada’s population growth rate is 0.8%. • Therefore, Canada’s doubling time is approximately 87 years (70/0.8).

20. Canada’s doubling time is 87 years. • Togo’s doubling time is 30 years (70/2.4). • Which country can more easily deal with its population growth? Explain.

21. Population Pyramids • It is easier and faster to understand population structure if the data are graphed. Two bar graphs are constructed. The first one looks like this.

22. Combine the two sets of bar graphs to create a population pyramid that shows the age/gender breakdown of a country’s population.

23. The second bar graph looks like this.

24. Dependency Load • The dependency load is the part of the population that needs to be supported. It is made up of two components: the 0–14 age groups and the 65+ age groups.

25. What has happened to the dependency load between 1956 and 2004? • What is the significance of this change?

26. Stages of Population Change • Populations within countries change over time in a predictable manner.

27. Have a close look at the Stages of Population Change diagram. • What is happening at each stage? • Why is it happening?