Here are some more news headlines from real observational studies. Determine at least one plausible lurking variable that could explain the cause and effect. Remember, do not argue about the link expressed in the headline. Accept the association as true. Your task is to determine the other variable(s) that could be the actual cause(s).
“The graveyard shift may be aptly named. Working nights will soon be listed as a likely cancer cause”
“Daily meat diet tied to higher chance of early death”
Answers for these problems will vary.
Graveyard shifts are usually in places where smoking is prevalent such as casinos, bars, and restaurants. Smoking is a known cause of cancer. Thus, smoking could be a lurking variable in this observational study.