For various reasons and in various ways, I sometimes wander around looking for old questions to close. (Think of me as the night janitor.) For example, a related question might come up in the list on the right that happens to be a duplicate of a current post that is also a duplicate. I can go to that question and vote to close it as a duplicate, but the probability that several other people will happen upon the same question, within the (I think) 1 week close vote timeout, seems to be pretty slim.
Here are a few examples that are in my queue at the moment:
- Find if a num is a power of 2 fast. (exact duplicate; I happen to know only because I answered the other one)
- fork() and child() processes in unix (no longer relevant; zero answers to a homework question that was due yesterday)
- Does anyone know a “working” Python library that can read .ARC files? (no longer relevant; OP asked about an ambiguous file format name, and re-asked the correct question later)
- Getting the domain TLD with PHP (exact duplicate; this one happens often)
A possible solution to this might be another moderator tool page would show a list of recent close votes. I sometimes try to visit the "most close votes" page before the UTC day rollover and spend my remaining close votes for the day on posts that deserve it, but posts with even 2 close votes never seem to show up on that list. A list of recent close votes whose posts are still open may be helpful.
I realise that ♦ moderator close votes are binding, so that's another possible answer. However, I don't think that the few diamond mods want to spend too much time trawling for old questions to close; this is a problem whose solution seems to involve the greatest number of eyes.
If I were to flag the post for moderator attention, it would likely get the job done quickly but removes some of the element of community input into close votes. Binding moderator closes always seem a bit heavy-handed to me, especially after just a couple of regular close votes.
I suppose some people might not consider this a problem at all, but I would suggest that without regular cleanup, the same questions will continue to be asked over and over in the long run, which dilutes the question pool and makes searching less focused (for example, I was a bit surprised to see the power-of-2 question appear again). Also note that I am advocating closing, not necessarily deleting in all cases, because there is value in differently-worded posts being pointers to a canonical answer.