Writer or Author

Guriko, here's how my ear and experience lead me to answer:

"I want to be an author" is an answer to "What role do you wish to have in the production of this book?" (Contrast "I want to be an editor" or "I want to be a marketing rep.") You refer to "an author" of a multi-author academic paper, too; so: "Stephen Hawking was an author of the article that appeared in Science magazine last month. Carl Sagan was one of the others."

"Writer" can be used, though it's not as nice-sounding, in any sense in which you could use "author." However, the reverse is not true. "Writer" is indeed the correct name of the profession of a person who seeks to be the author of a given work. It is true whether the writer is the author of a novel or a cookbook or even a newspaper society column.

Note, too, that you always see "the letter writer" and never see "the letter author," though you sometimes might see "the letter's author."

I think, in the context of declaring one's career ambitions, the only difference is that "author" sounds more pretentious.

Actually, journalists, columnists, and people who write for TV and movies are writers; people who write books can be called writers or authors.

A Writer writes, an Author inscribes meaning.

Roland Barthes for instance, forsaw the 'Death of the Author', not the end of journalism or novels et al. He saw the role of Authorship as no longer residing with the Writer, but shared between all powerful interests, ie The Audience, The Writer, The Producer/Publisher etc.

Writing therefor implies Labour, whereas Authorship implies Power and Agency.

So yes, it is VERY pretentious.

I don't know if this is really the best analogy, but, at least in some cases, the difference between a writer and an author is like the difference between a painter and an artist. Someone who paints your house isn't usually called an artist. Similarly, someone who writes TV sitcom scripts, or TV ads, or catalog descriptions, or user manuals for consumer products, may be a writer, but isn't an author.

Generally there is no pretense in the title of author. It simply means the writer is published. If you are writing, then you are not an aspiring writer because you are actively writing. You are simply a writer. If you are writing with the intention of being published, then you are an aspiring author. If you are a published writer then you are an author.