Did the paid-sharing crackdown actually cause the revenue lift?
Measure impactHardProblem. Netflix rolled out the paid-sharing crackdown (borrower prompts plus Extra Member), and in rolled-out regions revenue rose. Leadership wants to credit the crackdown with the full lift. Did it cause the lift, and how would you estimate the true incremental effect?
Before you reveal: say your answer out loud, as if you were in the real interview — get your reasoning across clearly first. There is no single correct answer: reading what the interviewer is really after and defending your own thinking is what makes an answer strong.
Strong-answer signal: leading with the assignment mechanism (staggered rollout), naming selection bias and its direction, and separating the causal estimate (DiD / synthetic control) from the raw before/after. Common trap: accepting the before/after lift as the program's impact, or jumping to a fancy method without justifying it from how treatment was assigned. Trains: non-randomization; confounder-direction.