I've been reading though a couple different blogs and one article I scrolled by was titled "I am a writer..." and it got me to thinking is the act of DM'ing really like being an author? Before I get too involved into it, I did have to Google if there was a difference between an author and a writer since they do tend to get used interchangeably and the first (and admittedly only) explanation I read was: "A writer is a person who writes a book, article, or any literary piece, while an author is essentially the person who originates the idea, plot, or content of the work being written. At times, the author and writer can be the same person." -- Source: TheDifferenceBetween.net
With this definition, I think that DM's really are the authors of their own campaigns. They originate the idea, plot, and content of the work, while it isn't necessarily written it the DM is the origin of the campaign. At the core of great DM's there needs to be an author that can take ideas, either from their own mind or from other resources, and convey them in a coherent plot. Once these ideas and concepts the DM can act as the writer to piece the concepts into a storyline. The only key difference from traditional writing to the writing style of a DM is that the written portion will be choppy and incoherent without the players. It is almost like playing D&D is the solution to writer's block. The DM can only plan so far ahead without knowing what situations will befall the heroes and the players decisions are the only ways to fill the gaps. In a strange sort of way, the DM writes the Mad-Libs framework and asks the players for the verbs to complete the story.
Every D&D campaign is a story that is controlled by choice so it cannot be traditionally written, but with the cooperation of a DM and a Party a story can begin developing. While the Mad-Lib will inevitably come to an end, the best part of Mad-Libs is reading back the choices that made the story what it is and that is always the best part of D&D. So are DM's authors? I would say that they are just as much the authors and the writers as the players are as one cannot function without the other. A DM can author a great premise and begin writing a story, but there will never be a final conclusion and cohesive story without the party to endure the challenges and steer the story in various directions.