<p>Not sure, but perhaps:</p>
<p><a href="https://stats.stackexchange.com/questions/tagged/mixed-model" class="post-tag" title="show questions tagged &#39;mixed-model&#39;" rel="tag">mixed-model</a> (5495) <span class="math-container">$\leftarrow$</span> <a href="https://stats.stackexchange.com/questions/tagged/random-effects-model" class="post-tag" title="show questions tagged &#39;random-effects-model&#39;" rel="tag">random-effects-model</a> (1450)</p>
<p>I suppose one can have a model with only random effects and no fixed effects, which would make it different from a mixed model, though I don't think the conceptual distinction is so large that it would merit a separate tag. And I think all the questions I've seen with this tag are about using random effects in mixed models.</p>
