<p>We do not have a problem with unanswered questions. We have a problem with low quality questions.</p>
<p>See the below image from <a href="http://data.stackexchange.com/stats/query/872670/scores-for-questions-and-answers-compared-by-month#graphhttp://data.stackexchange.com/stats/query/872670/scores-for-questions-and-answers-compared-by-month#graph" rel="nofollow noreferrer">this sql script</a> which gives for the monthly answers and questions the 10-log of the average score.</p>
<p><a href="https://i.stack.imgur.com/rk5Ts.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/rk5Ts.png" alt="10-log average score for questions and answers" /></a></p>
<ul>
<li><em>The overall decline</em> for both questions and answers makes somewhat sense, since it takes time to acquire votes. (It does make the voting system somewhat biased for older questions and answers, but I can not imagine that this is <em>very</em> problematic)</li>
<li><em>The relative decline</em> shows that the questions are now being less valued (relatively) than the answers (this is true for other stackexchange sites as well). This may indicate that the questions are becoming, on average, less good/valuable (at least in comparison to the average quality of the answers)</li>
</ul>
<p>So I believe we should not try to work on getting more questions answered, but instead on getting a better fraction of good questions.</p>
<hr />
<p><strong>Sidenote:</strong> We see that answers are getting relatively higher scored than questions, but this is not necessarily due to 'a change in the questions' (although I believe it is a factor). It might also be caused by answers getting better.</p>
<p>A possible mechanism is a selection effect. The users of stackexchange are being trained (by the voting system) not to give answers when they are likely not gonna attract votes.</p>
<p>People answering questions are more influenced by the voting system than people asking questions. The result of the voting system, aiming for bounties and hot questions, is that less attractive questions are also less likely gonna get an answer. That low score, less popular, questions are not getting answers is (nearly) an intentional part of the stackexchange formula.</p>
<p><strong>Total/Unanswered votes for questions above some score:</strong> It is interesting to check out <a href="http://data.stackexchange.com/stats/query/873168/questions-and-answers-per-month#graph" rel="nofollow noreferrer">this SQL script</a>, which looks at total questions vs unanswered questions considering questions with some minimal score. For questions with a score 2 or higher the gap starts to become smaller and questions with a score 5 or higher are nearly always answered.</p>
<p><a href="https://i.stack.imgur.com/zchxm.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zchxm.png" alt="gap disappearing for questions with higher scores" /></a></p>
<p><strong>answer rates for questions above some score</strong> The graph from <a href="http://data.stackexchange.com/stats/query/873181/questions-and-answers-per-month#graph" rel="nofollow noreferrer">this script</a> indicates an interesting drop in answer rate for questions with zero votes. Questions with <span class="math-container">$\geq0$</span> and <span class="math-container">$\geq1$</span> score have most of the time very similar answer rates except for a sudden shift in the last year where questions with <span class="math-container">$\geq0$</span> score have a particular low answer rate.</p>
<p>This shift is not something due to a change in the behavior, but the questions with 0 score and 0 answers get removed by community after one year.</p>
<p><a href="https://i.stack.imgur.com/eER9z.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eER9z.png" alt="comparing answer ratios for questions with different scores" /></a></p>
<p><strong>Questions with score &gt;1</strong> Thus the drop in answer rate has always been there and is an effect of the community requiring time to answer questions or remove bad questions (and hence you will see that more recent questions have a worse answer rate).</p>
<p>You can see these bumps in all of the graphs so these &quot;trends&quot; should not been seen as solely a change in behavior. Some better way of looking at it would be to <a href="http://data.stackexchange.com/stats/query/873201/questions-and-answers-per-month#graph" rel="nofollow noreferrer">select only the posts with score&gt;0</a>, in which case you still see a gap, but it is not increasing a lot in time (the absolute numbers might be even decreasing).</p>
<p><a href="https://i.stack.imgur.com/1qeGN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1qeGN.png" alt="only looking at posts with score above 0" /></a></p>
<hr />
<h3>Update</h3>
<p>When we look again at the script that compares the answered fraction as a function of the number of votes for the question, then we see that for specific categories (questions with 2 or more votes), the rate has been going up slightly.</p>
<p><a href="https://i.stack.imgur.com/Uk6XR.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Uk6XR.png" alt="new trend" /></a></p>
