<p>I am not sure how responsible the following is for the recent drop in answers per questions ratio (possibly not at all), but here is one thing I noticed and would like to bring it up in the context of this discussion.</p>

<p>I am following the [pca] tag and am trying to make sure that all of the questions related to PCA are either answered or closed. As there are not <em>so</em> many questions asked about PCA (maybe 1-2 per day), sometimes I feel like I have some time to go over the old unanswered PCA questions. I even have this silly dream of one day bringing the number of unanswered PCA questions to zero (from currently ~250).</p>

<p>Many of these questions are not very interesting. Many older questions are also quite specialized (e.g. asking about kernel PCA) <em>and</em> not interesting. What happens then, is that I write an answer which I think does quite a decent job in addressing the question and in the ideal world should be several times upvoted and accepted. But I often find that it remains with 0 upvotes (or 1 if I am lucky; probably also with ~0 views) and un-accepted (e.g. because the OP is not active anymore). </p>

<p>This is extremely frustrating. Why should I spend time answering these questions if <em>nobody</em> cares? Apart from me trying to empty the unanswered PCA queue, which sounds rather like a symptomatic internet addiction problem than a noble enterprise. </p>

<p>Especially frustrating is when the answer does not get a single upvote, so the question even <em>remains officially "unanswered"</em> even though I did answer it with the single purpose of making it answered!</p>

<p>I think by now I have some understanding of which threads are more likely to attract some attention, and the temptation is to answer only those. <strong>Update to clarify:</strong> My hypothesis is that something like that is happening at the population level: recent increase in the number of questions is due to an increased number of not-so-interesting questions, and potential answerers feel that such threads are simply not worth the effort. <strong>End of update.</strong></p>

<p>P.S. On a related note, what about old uninteresting and possibly unclear questions from non-active users with zero upvotes (that probably constitute the bulk of old unanswered questions). Is it a good practice to go through them and flag to close? Is it a good practice to downvote them silently, hoping that if they remain with -1 votes, they will eventually be automatically deleted?</p>

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<p><strong>Update.</strong> After writing this, I stumbled upon <a href="https://stats.meta.stackexchange.com/a/1248/28666">this older answer</a> by @whuber where he explicitly encourages to spend time writing few "high-quality, well-crafted" answers as opposed to many short ones. First, this directly goes against answering lots of questions just to have them answered and suggested carefully selecting only interesting questions. Second, if the number of not-so-interesting questions steadily increases, then this advice will inevitably lead to more and more unanswered questions.</p>
