Are most acts of sexual violence committed by a select particularly egregious few or by the presumably more common ‘casual rapist’? Answering this question is relevant for picking the strategies to focus on.
Lisak and Miller (link repeated for convenience: http://www.davidlisak.com/wp-content/uploads/pdf/RepeatRapeinUndetectedRapists.pdf) give decent data on the distribution. 91% of rapes/attempted rapes are from repeat offenders.
Are you assuming that crimes committed by people in EA will be towards other people in EA? According to RAINN, 34% of the time the sex offender is a family member. And most EAs have social circles which mostly comprise people who are not in EA, I would think. (This is certainly the case if you take the whole Facebook group to be the EA movement.)
I think that for all intents and purposes we should just use the survey responses as the template for the size of the EA movement, because if someone is on Facebook but is not even involved enough that we can get them to take a survey then we generally have little hope of influencing their behavior, if they even are in EA.
This seems like a well researched post with accurate statistics, but you didn’t note that EA is demographically somewhat different from the rest of the population. According to (https://bjs.gov/content/pub/pdf/SOO.PDF), 58% of American sexual assault offenders are white (this includes Hispanics), 40% are black, and 2% are “other”. Meanwhile the EA survey (http://effective-altruism.com/ea/1ex/demographics_ii/) showed that 89% of EAs identify as non-Hispanic white, 3.3% identify as Hispanic, 0.7% identify as black, and 7% identify as Asian (i.e. other). These stats are quite different from the base rate for the US, in a way that suggests the base rate of offenders in EA is lower than it is for the general population.
The 7.2 rapes per offender figure seems like it comes from a survey of paraphiliacs? Lisak and Miller say it is 4 rapes per offender. Maybe that is just because college students are younger.
I think that should be an obvious thing to do. Alcohol already costs money and reduces the intellectual caliber of conversation, we are better off without it.