Long Answer (45 points) Question 10

Stretching before exercise is often seen as a necessity but the empirical evidence on the benefits of stretching for performance and injury is mixed. Some studies find a positive correlation between stretching and injury. But is the relationship causal? 3

(a) Provide an argument for why the correlation between stretching and injury might be the result of reverse causation.

(b) Identify two confounders that you think might make a causal interpretation ofthe correlation between stretching and injury problematic. For each, explain why you believe the confounder might affect both treatment (stretching) and outcome (injury).

(c) Sign the bias for each of the confounders you identified. Having done so, explain whether each tends to make the observed correlation between stretching and injury an over- or under-estimate of the true causal effect.

Would you please answer this question and provide an explanation. I appreciate your help.

Thank you