That is often one of the pieces of information agents ask you to include in your query letters - for fiction. But how does one answer that question? What makes someone qualified to write about zombies or magic amulets? Have you ever been in contact with the living dead or found an other-worldly piece of jewelry in your Grandmother's attic? Chances are - no.
So what exactly are they looking for? (and it's not writing credits because that is in itself an additional question) Am I qualified to write about teen romance? Yes. Why? Because the number of boyfriends I had exceeds the double digits and we don't even want to talk about the number of boys I dated that never evolved into actual boyfriends. But somehow I get the impression that is not a piece of information I should put in my query letter.
So dear agents, please explain, what exactly are you looking for when you ask this question? And if I'm writing about zombies should I just ignore it?