AreR > between 2/3 and 3/4 of his members are men.
So, maybe his organization is a good place to call for shidduchim for girls? 🙂
so for 12% of Litvish leaving O-, this would be an extra 4% inbalance. I don’t think this rule would apply to the 30% Sefardim, as the number above that I saw quoted, as these are less dramatic cases of parents moving from traditional Sephardi to “haredi” lifestyle, and their children relaxing back to some degree.