<p>It is possible for moderators to switch which thread is considered the master and which is the duplicate.  It isn't necessarily the case that the oldest needs to be the master&mdash;the thread with the best answers can be (see: <a href="https://stats.meta.stackexchange.com/q/4826/">If question A came before question B how can A be a duplicate of B?</a>, and <a href="https://stats.meta.stackexchange.com/q/2569/">Many (historical) duplicate questions - how to pick a “canonical” question?</a>).  However, a legitimate issue is whether a moderator should override the status quo based on a single flag.  A reasonable approach is that if there is any ambiguity, the question of which would serve as a better master could be raised on meta.CV.  </p>

<p>In this case, the two threads clearly overlap, but also both have nonoverlapping elements.  My guess is that the most conservative option is for neither to be marked as an exact duplicate.  I think little is lost by this.  </p>

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<p><em>Update:</em> I switched "A" to be a duplicate of <a href="https://stats.meta.stackexchange.com/questions/5392/answer-in-question-marked-as-duplicate-is-superior#comment16410_5392">@amoeba's</a> suggested <a href="https://stats.stackexchange.com/questions/122974">thread</a>.  It's clearly a better target.  In addition, I closed "B" as a duplicate of a list of threads that address the various questions raised, starting again with @amoeba's target, but also threads pertaining to the assessment of heteroscedasticity and alternative testing strategies in the presence of heteroscedasticity.  </p>
