This straightforward question has a couple of straightforward limitations. For one, we might expect people who are involved in almost any activity to say that they benefit from it; self-reported benefit does not necessarily indicate actual benefit.

Well, the serious issue that comes to mind is selection bias. If someone thinks that LW is a -3 for them, are they going to stick around and take the survey?

But I don't think that's as important for asking the question of whether people who are already here should try to increase or decrease their involvement in the community, so there's still value in doing this analysis.