<p>This strikes me as a good and productive conversation (+1 to everybody).  I just want to offer another option for dealing with these situations, and that is to comment on the main question leaving a link to other questions with related information / material.  (Of course, when someone votes to close as a duplicate, this is done automatically.)  I'm not saying we need to always go this route, but it's a nice option to hold in mind.  </p>

<p>This approach will offer many of the advantages listed by @whuber.  Among other things, it will also help Google find the best answers on CV, because there will be more links pointing to the best threads.  </p>

<p>Another issue is that I often find there are subtle differences in questions that are listed as duplicates, which can invite differing, but equally valid, answers.  As a case in point, there was a question a while back where the OP said that they had taken a log transformation of a covariate to approximate normality, but found that they could no longer interpret it, and asked how to interpret a log transformed variable.  This was merged with another question on how to interpret log transformed variables, but before it was merged, I had answered that the distribution of covariates didn't matter.  My answer no longer made any sense in the new context, so I deleted it.  (For the record, I'm not complaining here, I'm perfectly fine with the questions having been merged.)  Should a case like this exist, commenting and linking is another option that can be considered.  </p>

<p>With respect to the thread in question, I had voted not to close, and later to reopen.  However, I'm open to the idea that I'm wrong on that one.  I have also noticed times in the past when I voted to close a question, but others voted to keep them open.  I suspect it is only natural that there will be cases where opinions vary.  </p>
