<p>There is &quot;zero-inflation&quot; the <em>phenomenon</em>, and there are zero-inflated-(Poisson / negative binomial / etc.) <em>models</em> as one strategy to deal with that phenomenon (in addition to hurdle models and possibly other strategies).  I interpret the tag to be about the phenomenon.  The excerpt should be clarified to eliminate the conflation of phenomenon with one possible remedy.  Here is a possible edit:</p>
<blockquote>
<p>Count variables often have excess zeroes compared to a specified count distribution. Less commonly, continuous data can have this issue, use [point-mass-at-zero] for that.</p>
</blockquote>
<p>We could further create tags for various existing approaches to dealing with the phenomenon, such as <code>[zero-inflated-poisson]</code>, <code>[zero-inflated-neg-bin]</code>, <code>[hurdle-model]</code>.  I do wonder how well so many specific tags will fare in practice, though.  My guess is that a question could be tagged with <code>[zero-inflated]</code> and <code>[poisson-regression]</code>, e.g., and do just fine.  That is somewhat inconsistent with having <code>[hurdle-model]</code> as a stand-alone tag, but I think it may be a workable compromise until there are sufficient threads to merit revisiting the issue.  Or not, I'm about 50-50 on this...</p>
<p>Another possibility is to change the existing tag from <code>[zero-inflation]</code> to <code>[zero-inflated-data]</code>, and then have a generic <code>[zero-inflated-model]</code>.  That would be less open to error.  My basic suggestion here is to add / clarify the excerpts and otherwise leave it alone as much as possible.</p>
<p>To answer your specific questions:</p>
<ol>
<li><p>I wouldn't make <code>[hurdle-model]</code> a synonym of <code>[zero-inflation]</code></p>
<p>But we should clarify the excerpt for <code>[zero-inflation]</code> as pertaining to the phenomenon.</p>
</li>
<li><p>I wouldn't make <code>[point-mass-at-zero]</code> a synonym of <code>[zero-inflation]</code></p>
<p>But we should create a good excerpt for it.</p>
</li>
</ol>
