Grade 9 Geography Unit 4 - Population Pyramids Expansive A broad base, indicating a high proportion of children, a rapid rate of population growth, and a low proportion of older people. Nunavut is an example of an expansive type population pyramid. Stable growth A structure with indentations that even out and reflect slow growth over a period. Northwest Territories is an example of a stable type population pyramid. Stationary A narrow base and roughly equal numbers in each age group, tapering off at the older ages. Manitoba is an example of a stationary type population pyramid. Declining A high proportion of aged persons and declining numbers. Newfoundland and Labrador is an example of a declining type population pyramid. The Population Pyramid and How it works Bar graphs are a handy way to illustrate numbers. For example, graphing the number of males and females in Canada for various age groups according to the 1961 Census, the result would be Figure 1 and Figure 2. Figure 1. Percentage of Males in Canada as Percentage of the Entire Population in 1961
Figure 2. Percentage of Females in Canada as Percentage of the Entire Population in 1961. Displaying these two graphs together, horizontally and as a mirror image, we make a Population Pyramid (see Figure 3). Figure 3. Population Pyramid for Canada, 1961
Figure 3 shows, at a glance, the distribution of the Canadian population in 1961. Features and interpretation of this pyramid. The pyramid narrows toward the top. This is because the death rate is higher among older people than among younger people. There are also a few bulges and narrower parts in the middle part of the pyramid. For example, there are not as many people in their 20s as in their 30s in Canada in 1961. The people in their 20s in 1961 were born at the end of the Depression and the start of WWII. This was a time of economic hardship and uncertainty. People were having fewer children in this period. In 1961, the pyramid had a wide base. Adding the percentages for the three lowest age groups, we find that 35% of the population was under 15. These are the baby boomers, a large group of people born between 1947 and 1966 when the economy was growing and prospering. By analyzing population pyramids and identifying trends, we can learn a lot about our present society and future trends. There are three key types of population pyramids. Rapid Growth The triangle shape suggest rapid population growth. Slow Growth - The square-like structure is slow growth. The lump in the pyramid between the ages of about 35 to 50 is the post-world War II "baby boom." As this population ages and climbs up the pyramid, there will be a much greater demand for medical and other geriatric services. Negative Growth - The population is shrinking due to a low birth rate and a stable death rate. Increased emigration may also be a contributor to a declining population.
Task 2001 Population Pyramid for Canada Data are provided from the 2001 Canadian Census of Population giving the population by five-year age groups and sex. Using the data, make a 2001 Population Pyramid. Canada s Population by Age Group and Sex 2001 Census of Population Age Group % Men % Women 0-4 2.9 2.8 5-9 3.4 3.2 10-14 3.5 3.3 15-19 3.5 3.3 20-24 3.3 3.2 25-29 3.1 3.2 30-34 3.4 3.6 35-39 4.1 4.3 40-44 4.2 4.4 45-49 3.8 3.9 50-54 3.4 3.5 55-50 2.6 2.7 60-64 2.1 2.2 65-69 1.8 2.0 70-74 1.5 1.8 75-59 1.1 1.6 80-84 0.6 1.1 85-89 0.3 0.6 90+ 0.1 0.3 Males on the left, age groups down the middle and females on the right. The x- axis is the Percentage of Total Population.
Questions Use your 2001 Population Pyramid to answer the following questions. 1. Write the details of your age group and sex within the Canadian population Age group Sex Percentage 2. What single age group and sex represents the largest percentage of Canada s population? Age group Sex Percentage 3. Circle the 10-year age group that contains the largest percentage of the population. 0-9 10-19 20-29 30-39 40-49 4. What percentage of Canada s population is male and what percentage is female? (Add the percentages for each sex.) Males Females 5. Write in the percentage for males and females age 65 and over. Males Females Comments 6. Explain why the 2001 population pyramid has a narrower base than that of the 1961 pyramid (Figure 3). 7. Populations are frequently divided into two categories: (1) people who are of working-age (15-64) and (2) people who are not of working age (under 15; 65 and over). Give the percentage for each category in 2001: Working age Not of working age How could the working-age population contribute to Canada s economic growth? List five examples.
Why is it important to understand or examine the changing trends in working-age populations (i.e., compare 1961 to 2001)? 8. Why would leaders of a country want to know the proportion of the population in different age groups? What difference does the age of the people in a country make? Provide three examples. TOTAL FERTILITY RATE Another element of Population Pyramids is Total Fertility Rates (TFR). It is the single most important factor in determining future population. TFR is the average number of babies born to women during their reproductive years OR the sum of the age-specific birth rates of women in five-year age groups. Note - Fertility rate is the number of children born alive per thousand fertile women per year. A TFR of 2.1 is considered the replacement rate. Once TFR reaches 2.1, the population will remain stable assuming no immigration or emigration takes place. When TFR is greater than 2.1, a population will increase. When it is less than 2.1, a population will decrease, although due to the age structure of a population it will take years before a low TFR is translated into lower population. Although still high in many parts of the world, TFR has been declining dramatically over the past decade. As shown in Table 1, the TFRs in the developed countries (e.g., Canada are below the replacement rate, although in many of these countries population continues to grow due to the age structure of the population as well as immigration. Currently 61 countries have a TFR of 2.1 or less (Canada s 1998 TFR was 1.7). The TFR for less developed countries is twice as high as the developed countries. However, it is falling -- TFRs in less developed countries dropped almost 40 percent from 4.7 in 1990 to 3.1 in 2000. Although the cause is debated, there is no doubt that women all over the world are having fewer children. Table 1. World Total Fertility Rates (Observed and Predicted). Region 1990 TFR 2000 TFR 2010 TFR 2020 TFR World 3.4 2.8 2.5 2.3 Less 4.7 3.1 2.7 2.4 Developed Countries Developed Countries 1.9 1.6 1.7 1.7
Source: www.overpopulation.com/faq/basic_information/total_fertility_rate Niger has the world s highest TFR at 8.0 children.
We know the TFR for the developing countries is slightly above replacement. Now, let us look closer at various regions and incomes Table 2. TFRs for Various Regions and Incomes of the World Factors 1970 TFR 2000 TFR Least Developed 6.6 5.1 Arab States 6.7 3.8 East Asia and Pacific 5.0 2.0 Latin America and Caribbean 5.1 2.5 South Asia 5.6 3.3 Sub-Saharan Africa 6.8 5.4 Central and Eastern Europe 2.5 1.4 High Human Development 2.5 1.8 Medium Human Development 4.9 2.4 Low Human Development 5.8 5.6 High Income 2.2 1.7 Middle Income 4.6 2.1 Low Income 5.7 3.7 Question 9. Provide an interpretation of Table 1 and Table 2. Include three ideas for each table.