Question: A headline in the Sacramento Bee (11 December 1997, p. A15) read, "Study: Daily drink cuts death," and the article began with the statement, "One drink a day can be good for health, scientists are reporting, confirming earlier research in a new study that is the largest to date of the effects of alcohol consumption in the United States." The article also noted that "most subjects were white, middle-class and married, and more likely than the rest of the U.S. population to be college-educated."

a. Explain why this study could not have been a randomized experiment.

b. Explain whether you think the headline is justified for this study.

c. The study was based on recording drinking habits for the 490,000 participants in 1982 and then noting death rates for the next 9 years. Is this a retrospective or a prospective study?

d. Comment on each of the "difficulties and disasters in observational studies" (Section 5.5) as applied to this study.