When assessing the risk of suicide, there are two competing theories: coupling and displacement. “Coupling” means, when the method of suicide is blocked, suicide is stopped. “Displacement” m

Question 1. When assessing the risk of suicide, there are two competing theories: coupling and displacement. “Coupling” means, when the method of suicide is blocked, suicide is stopped. “Displacement” means, when one method of suicide is blocked, suicidal individuals will simply use another method.
The Golden Gate Bridge in San Francisco has been the site of more than 1500 suicides since its opening in 1937. No other site in the world has seen so many suicides. The city wants to do something about it. You have been asked to find out whether suicide by jumping off a bridge follows the path of coupling or displacement.
1) How would you design a prospective study to answer this question?
2) Which threats to internal and external validity would you expect in this prospective study? List the threats and briefly explain.
3) Alternatively, how would you design a pre-test post-test study to answer this question?
4) Which threats to internal and external validity would you expect in this pre-test post-test study? List the threats and briefly explain.
5) If coupling is more likely, what would you recommend that the city do?