<p>See this post:</p>

<ul>
<li><a href="http://meta.stackexchange.com/questions/78048/auto-deleting-old-unanswered-zero-score-questions-after-a-year">Auto-deleting old, unanswered zero-score questions after a year?</a></li>
</ul>

<blockquote>
  <p>We already auto-remove negatively voted unanswered old questions automatically after 30 days, network wide, with no human intervention required.</p>
</blockquote>