Are You a Writer, or an Author? Part III

Webster's etymologies, as far back as they can be traced:

author: "to increase, produce"

writer: "to scratch; to tear"

I think writers do both. The difference seems to be that writing is composing, and authorial actions are quantifiable or measurable. As in:

Have you written the next chapter of your novel?
Have you authored your 1500 words today?

"Author" and books are related because published books can be counted. Most people have no other way to take the measure of a writer.

OK -- this question's settled. Now: Have you written the next chapter of your novel? Have you authored your 1500 words today?