Question: Explain why the following claims might not imply causal relationships and outline how you would test for a causal effect using an experimental methodology with a treatment and control group:
a. People with larger feet earn more money.
b. Smokers earn less.
c. People with college education earn more than people with only high school education.
d. Children born into families that receive welfare are themselves more likely to receive welfare when they attain adulthood.