Given two duplicate questions, are there any guidelines on how moderators determine which question is closed/merged, and which question will remain open, or is it up to the moderator to decide on a case-by-case basis?
I've seen a number of merged questions, where sometimes the earlier of the two questions is kept, while sometimes it's the better worded question; when a question is migrated and the OP doesn't have an account on the new site, it might be merged to the question that has an account (or is more active).
I'm not criticizing any of these decisions. I'm just curious if there is any policy (written or otherwise) on how moderators should decide the direction-to-merge. (And if so, what it is.)