Conditioning on a collider opens a fake path
Two unrelated traits, skill and luck, both influence whether a fund survives long enough to enter your sample. You study only surviving funds and regress performance on skill, controlling for (or effectively conditioning on) survival.
Explain how conditioning on survival can induce a spurious negative relationship between skill and luck, and why this is a bad control, not a fix.
Your answer
This one is open-ended. Work it through, then check your reasoning against the full solution.