<p>You can migrate a question by flagging it yourself, which allows you to send a message to all moderators with your request.  It's hard to imagine a circumstance in which this would be denied (unless the question is too ill-posed, in which case it would just be closed anyway).</p>

<p>BTW, I wouldn't read too much into audience size.  My experience with the math and stats sites is that when stats questions involve <em>anything</em> to do with actual data, you are far better off posting on the stats site.  When the questions are theoretical, as yours have been, it's hard to know where to go.  A clear, well-posed question will get attention on both sites.  If it turns out that the answer needs simulation, data analysis, or research, you're likely to get that answer here.  If it succumbs to purely mathematical techniques, math.SE is probably the best place for it.  But it's often hard to know in advance what the solution will look like.  In that case guess, wait a few days, and have the question migrated if there's no useful response.</p>
