Power of the Pyramids

Objective:

To develop an understanding of how to interpret age pyramids and understand the relationship between age structure and human population growth.

Background:

Population growth is affected by age structure - the number of individuals in different age groups - as well as by the numbers of births and deaths. Age structure is usually illustrated by an age pyramid, a graph in which horizontal bars represent the percentage of the population in each age group. Males are shown on the left and females on the right. The ages (or in some cases, the years of birth) for each bar are listed along the vertical axis of the graph, usually in five-year intervals. Each age group is called a cohort. The longer a bar is, the greater the proportion of individuals in that age group.

Age pyramids are useful for tracing the history of a population and for projecting future population trends. An age pyramid with more long bars for the younger age groups would indicate a growing population; when these large numbers of young begin to reproduce, they will add even more offspring to the population than did the older age groups.

Part 1

Procedure:

Use the following link to answer the questions below with regards to the country you were assigned.

 http://www.census.gov/ipc/www/idbsum.html

Your country is:

Analysis:

1. Where is your country located?

2. Is your country a developing or developed nation?

3. What is its crude birth rate (CBR)?

4. What is its crude death rate (CDR)?

5. What is its rate of natural increase?

6. What is the life expectancy? 7. What is the infant mortality rate?

8. What is the total fertility rate (TFR)?

9. How has the growth rate changed since 1950?

10. What is the growth rate today?

Part 2

Procedure:

1. Complete Table 1: Population Distribution for your assigned country and year. Population data can be found at:

 http://www.census.gov/ipc/www/idbagg.html

Fill in the following search parameters:

 094 Population by Age and Sex  Spreadsheet mode  5-year ages  Population and sex ratio  Treat each region separately  Country data only  Select country  Select year  Translate all coded information  Country and year only shown on a separate line  Submit Query

2. Use Microsoft Excel to create a population pyramid for your assigned country/year.

 Use a bar graph  Make sure you title and label axes appropriately on your graph  Click here for an example

3. Answer the questions below.

Analysis:

1. Which gender has the higher population in the youngest age groups on your pyramid? Can you account for this?

2. Which gender has the higher population in the oldest age group? Can you account for this? 3. Does your country look like a pyramid?

4. What can you tell about your country's growth rate by looking at your graph?

5. If birth and death rates remain the same, what will your pyramid look like in 25 years?

6. What are some factors that could change the shape of your pyramid?

7. Determine the percentage of the population that has yet to reach childbearing age. What do these numbers say about the prospects for future growth?

8. If your country is not increasing in population growth rate, what are some socio/economic problems that might occur?

9. Can you determine from your graph how many people make up the population of your country? Why or why not?

10. Does your country have a bay boom in it? (a bulge somewhere in the middle) What could account for this?

11. If you had a business and you wanted to capitalize on your information about the population age distribution, what would you sell?

12. What percentage of the population is above age 65?

13. Does your pyramid look like that of the World Population Pyramid?

14. From the information on your graph/histogram, briefly discuss whether the country is increasing in population size, decreasing or at/close to zero population growth (ZPG).

15. From your data and graph/histogram, would you place the the country in the category of developing or developed country? Explain.

Table 1: Population Distribution

Table 1: Population Distribution Age Groups Male % Female % 0-4 . . . . 5-9 . . . . 10-14 . . . . 15-19 . . . . 20-24 . . . . 25-29 . . . . 30-34 . . . . 35-39 . . . . 40-44 . . . . 45-49 . . . . 50-54 . . . . 55-59 . . . . 60-64 . . . . 65-69 . . . . 70-74 . . . . 75+ . . . . Total . . . . Total . Poulation