# Lesson 11: Projections and the Census

Strand: Managing Data

Skills and Objectives

• Connect data and history in their study of previous population booms
• Access a wide range of census data
• Analyze census data in order to make predictions about the future

Materials: Projections and the Census Student Worksheet 11

Time Required: One 40-minute class period

Getting Started

1. Explain how census data are used for a variety of important purposes. The data are especially useful in tracking large population changes in the United States. The Census Bureau even uses the data to develop projections for population figures. Projections are calculations of data for a future date. There are two different kinds of information that are needed to create an accurate projection: past data and an estimated rate of growth or decline.
2. Explain to students that, with regard to the census, methodology is the way data are used to make projections. The methodology that the Census Bureau uses is called the cohort-component method. This method bases projections on estimated population as well as on other components of population change: births, deaths, internal migrations, and international migrations. These components come from various sources including the decennial census.
3. Tell students that census projections are highly valued by both public and private entities. Ask students why they think a government official or business owner might want to be able to predict population changes. Discuss how the government needs to know where to build schools and hospitals and how business owners need to know where to locate stores and target marketing efforts.
4. Using Student Worksheet 11

5. Distribute copies of Projections and the Census Student Worksheet 11. Guide students through a case study to explore the ability of censuses to predict changes in population.
6. Instruct students to use www.census.gov to find historical census data, in particular the change in state populations after 1900. If they need more guidance, tell students to look under “Special Topics” to find the Statistical Abstract link. Click on that link and then click on Historical Statistics on the right-hand side.
7. Divide students into pairs and guide them in answering the questions in the case study. At the end of the case study, discuss how the census tracked the changes in Michigan’s population and how the data were used to make projections for the changes in population later.
8. Guide students in conducting research for their essay titled, “What Will the United States Look Like in 2020?” Their primary resource should be the Census Bureau’s American FactFinder Web site at http://factfinder.census.gov.
9. Remind students to keep track of the sources of their data. They should have statistical evidence to support their projections.
10. Wrap-up

11. Send students on a hunt for old population projections from the 20th century. Have them compare these projected sets of data to the actual numbers. Encourage students to analyze how successful these projections were.

1. 16.1%, 30.5%, 32.0%, 8.5%, 21.2%
2. Car production
3. World War I
4. The 1910s
5. That it would increase greatly.
6. It increased greatly.

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