They used to publish the effectiveness but quit in the early 80's. It's easy to track anonymous users when the same anonymous users show up for the same meetin

They used to publish the effectiveness but quit in the early 80's. It's easy to track anonymous users when the same anonymous users show up for the same meetings for years. AA has had a LOT of meetings over the years, so coming up with a baseline of effectiveness isn't a vexing problem. Why they quit publishing those numbers isn't exactly a mystery, either.