Dearest Query Shark,
When I write my query letter for my Young Adult novel, should I mention the fact that I have published two academic history books with university presses? Or will such information just seem obnoxiously irrelevant, given that the novel is not historical fiction?
There are two questions here.
1. If I mention this will I look obnoxious?
2. Will it help me to mention it?
The answer to both is no.
But the real answer is it won't hurt you, either.
But the best answer is: don't take up scarce real estate in a query (remember you've only got 250 words!) with something that isn't a plus.
While two academic history books are indeed a publishing credit, they are not the kind of writing you're doing now; they're sold to entirely different markets, and in entirely different ways.
The publishing credit that does help you are books or stories that were acquired for a trade audience. Not necessarily YA but trade in general.
Bottom line: I never passed on any project that interested me cause the author didn't have any pub credits, or had pubbed Studies in Shark Bites: An Analysis of Query Letters Received by Barbara Poelle.