<p>Homework problems have a special status here.  One aspect of this is that we want them marked with the <a href="https://stats.stackexchange.com/questions/tagged/self-study" class="post-tag" title="show questions tagged &#39;self-study&#39;" rel="tag">self-study</a> tag.  However, I think the tag needs to be added almost exclusively <em>by the OP</em>.  I leave a comment, of varying levels of severity (there are examples listed <a href="https://stats.meta.stackexchange.com/a/2486/7290">here</a>), for the OP to add the tag and read its wiki.  There are several reasons for this:  </p>

<ol>
<li>If the OP adds the tag, they are more likely to have read the wiki and be familiar with our policies.  </li>
<li>Adding the tag is a positive action on the OP's part that communicates some buy-in; i.e., that they will abide by our polices.  </li>
<li>If the OP does not add the tag, that is a concrete signal that the thread should be closed.  </li>
</ol>

<p>Adding the tag for the OP obscures all three.  </p>

<p>Another issue is that adding the tag to a thread that was closed for not meeting our standards bumps the thread into the reopen queue.  Reopen is one of our slowest and least reviewed queues (in part because it takes the highest reputation to access).  So these threads often just sit there for a long time, only to eventually be marked to be left closed (since, again, the OP has not taken any action to meet our standards).  Moreover, if the OP does edit their question to meet our criteria afterwards, their question <em>will not</em> necessarily be bumped back into the reopen queue, since it was reviewed already.  </p>

<p>I have a hard time seeing under what circumstances it would be better to add the tag for the OP, rather than them adding it for themselves.  @Silverfish's scenario in which </p>

<blockquote>
  <p>the question has been around for a long time, is blatantly self-study, and especially if the OP is no longer active... and have had good answers posted to them... in this case I might just edit and add the self-study tag  </p>
</blockquote>

<p>seems eminently reasonable, but that strikes me as an infrequent occurrence.  </p>
