Earlier this week, I wrote about the challenge of writing a book when you've been trained to write journal articles—two very different forms with different logics, different readers, and different demands. You can read that article here:
Today’s episode stays broadly in that same vein but focuses on a question I hear frequently from scholars who are working on academic books: how much of my previously published material can I include in my book?
You’ve probably heard some version of this advice already: “No more than 25% of your book should have been previously published.” Some people frame it as chapters—“no more than one or two.” The numbers may shift depending on who you talk to, but the anxiety they produce is remarkably consistent. The moment you hear a figure like that, most of us start doing involuntary math, counting up chapters and estimating overlaps and wondering whether we’ve quietly ruined a book we haven’t even finished.
In this episode, I try to offer some relief from that spiral — not by dismissing the 25% figure, which does reflect a real concern in academic publishing, but by explaining what it actually means and, more importantly, what it doesn’t mean. That number circulates the way a lot of publishing lore does, passed from senior to junior scholar in a conference hallway, until it starts to sound like official policy handed down from somewhere authoritative. It isn’t. What it is, I’d argue, is a rough threshold—a signal that it’s time to look more carefully at the nature of the overlap, not a verdict on your manuscript or its publishability.
The more important question, and the one acquisitions editors are actually asking, isn’t how much of your material has appeared before. It’s whether your book offers readers a substantially new intellectual experience. Those aren’t the same question, and the gap between them is where most of the real work of revision lives.
I talk through what that means in practice—what transforms an article into a chapter, what doesn’t, and what you should be able to say when an editor asks you directly about the overlap. I also get into a few factors that don’t always come up in these conversations but that genuinely shape how an editor will read your manuscript: the extent of the revision, the press you’re approaching, and yes, some of the harder structural realities of how prestige operates in academic publishing.
