The most recent convocation of the Islington Comics Forum (a local institution where I now get my words + pictures from) had this on the agenda, and there was just too little time to dig into one of the central questions posed by the book, which is why in the seven hells is it called Ghost World? The phrase is graffitied everywhere around the unnamed town the characters inhabit, and one semi-official explanation is that it refers to "the fact that the town's individuality is being encroached upon by franchises that are seen everywhere". But what about that sequence at the very end of the book, when Enid comes across the mysterious artist responsible for the graffiti? What's THAT about?
Earlier in the book, Enid is excited about meeting "David Clowes" – a stand in for the author of her comic – at a signing. The guy turns out to be a creep, and Clowes may be aiming this episode at writers unselfconciously creating their very own fantasy girlfriends in their work. Clowes is not doing that, and I learn just now that Enid Coleslaw is actually an anagram for Daniel Clowes, which further underlines his determination to keep his protagonist very close, not letting any 'other-ing' distort his account.
That piece of meta prepares us for Enid's second encounter with a manifestation of her author. Because that is who I believe the guy with the paint can and brush leaving all those "Ghost World"s is. Clowes is literally branding his creation, imposing a unifying metaphor over it. But as his central character approaches for answers, he literally runs away from providing any. In that scene, he divests himself of the responsibility of giving a moral to his tale, or a direction for Enid. The book ends on the exactly the opposite of a deus ex machina – God isn't revealed in the machine, He leaves it.