# Study Questions

### Chapter 1

The American Community Survey (ACS) provides an annual profile of population and housing trends in the United States¹. Topics covered in this report include, but are not limited to, the following: population demographics, households and families, nativity and language, geographic mobility, education, disability, poverty and participation in government programs, and housing characteristics.

1. The report notes that, "In 2007, United States had a total population of 301.6 million - 153.0 million (51 percent) females and 148.6 million (49 percent) males." What is the unit of analysis here?

2. From the statement in Question #1, male and female are two classes or values of what variable?

3. From Question #1, if the total U.S. population was 301.6 million in 2007, then the variable of interest here is population size. What is the level of measurement for this variable?

4. Is U.S. population a continuous or discrete variable?

5. The report goes to say that, "Twenty-five percent of the population was under 18 years and 13 percent was 65 years and older." How is the age distribution of the U.S. population being measured here? In other words, what is the level of measurement based on the statistics provided in this statement?

6. Suppose that a researcher advanced the hypothesis that national level poverty rates vary by age. What is the dependent variable here? What is the independent variable?

7. After advancing her hypothesis in Question #4, the researcher came across the following statement in the ACS report: "In 2007, 13 percent of people were in poverty. Eighteen percent of related children under 18 were below the poverty level, compared with 10 percent of people 65 years old and over." Does this finding appear to support her hypothesis advanced in Question #4? Why or why not?

8. After reading the statement in Question #5, the researcher is still not convinced that she has uncovered a causal relationship between age and poverty. As discussed in Chapter 1, what two conditions necessary for establishing causality has she not satisfied?

9. The same ACS report also provides information on the educational attainment of the U.S. population in 2007. The report notes, "In 2007, 85 percent of people 25 years and over had at least graduated from high school and 28 percent had a bachelor's degree or higher." What is the level of measurement for educational attainment?

10. Given your answer in Question #7, what do we know about the categories for educational attainment? Are they ordered (i.e., ranked)? Can we tell how far apart each of the categories is on some metric (e.g., years)?

11. Suppose that a researcher advances the following hypothesis: the national level poverty rate will begin to decline slowly if there is a preceding increase in the proportion of Americans completing college. Identify the independent and dependent variables.

12. From Question #10, identify the level of measurement of each variable. (Hint: pay attention to two key words - "rate" and "proportion."

13. Suppose that a researcher advanced the hypothesis that national level poverty rates vary by education. What is the dependent variable here? What is the independent variable?

¹The complete version of the report is available here, with all citations in this set of exercises are taken from the following: http://factfinder2.census.gov/faces/nav/jsf/pages/index.xhtml