I was quite surprised by this question in a conversation at WFC this past weekend, when I was informed (in all good will) that while I might be a new writer, I wasn't a young writer. Now, although I occasionally kvetch about the ragged fletching on time's arrow, I by no means consider myself old. This was quite a surprise to me. I am firmly past 40, but not anywhere near the next roll of the decennial odometer.
It's a question which has occurred to me before. I recall a few years ago reading a review of some of my friend Ray Vukcevich's work, which referred to him as a "new writer." At the time, he was some ten years past his first appearance in F&SF, had several dozen pro credits, a novel and a collection out. He is also roughly the same generation as my parents. I was croggled that a man with 20+ years on me and a ten-year publishing career could be considered "new."
For the most part, I've quit referring to myself as a "new writer", or even really thinking that way. My first professional short fiction sale appeared a hair more than six years ago, in September of 2001. (I was 37 at the time.) Mainspring [ Powell's | Amazon ] is only a few months on the market, so it might be fair to call me a "new novelist", but even that is somewhat belied by my prior work in the independent press.
I sometimes talk about my generation of writers, but when I do, I'm thinking of people who started publishing within a few years of the turn of the century, either way. There's also a sense of being a cohort, a sense of peering, at least among some of us. I'm talking now about writers such as tim_pratt, scalzi, davidlevine, matociquala, kenscholes and tobiasbuckell. We're united by a common thread of experience (most of those folks are Writers of the Future alumni), a common thread of publishing history (most of those folks emerged during the current small press boom, though not all of them used that path), a common thread of promotional style (most of those folks have blogs and blog audiences).
Still, it's true that I'm pretty much chronologically the oldest of that cohort, even though most of them hit the bigs before I did. Sometimes this bothers me. What if I'd found the key to this lock when I was 27, or 17, instead of 37? That kind of thinking is a fool's game, at least outside the written word — I wouldn't have the_child in my life, for one thing. I am who I am. Most of the time I just don't feel old about it.
So how do you count the age of a writer? Publication age? Publication density (like dog years)? Birth certificate? Peer grouping? Heck if I know. There's a part of me which will always be a wide-eyed newbie, and there's a part which is already cynical and jaded. Splitting the difference is the real trick. That, and laughing at time.