In his new book Post-Westerns Neil Campbell explains his rationale for using the term with the hyphen, and it would seem pertinent to the thought that using the hyphen after the “post” relates to discussions of genre (Neil is addressing film westerns in the book).

And yet, with regard to Krista Comer’s recent introduction to the WAL special issue devoted to younger scholars and with regard, as Sara mentions, to Susan Kollin’s edited collection, “postwestern” appears to have  become—as is the case with “postmodern”/”postmodernism”/”postmodernity”—the authoritative term. I would only add that “post-western” with the hyphen suggests a decisive break with modernity/modern, which is problematic. “Postwestern,” like “postregional (my preferred term for what it’s worth), suggests an orientation toward an emergent condition, but one where the residue of the past still obtains. If one considers as well the occasional use of a term/concept like “post-postmodernism,” then using another hyphen if one wanted to talk about “post-post-western” seems out of joint.