How do you/other agents feel about having a book you represent listed in an author’s book proposal competition section? It makes sense that an author might reference a book you represent — and that if the book is similar, it would make sense to list it as competition. But then…
*** Please note that this is going to appeal primarily to nonfiction writers of self-help nonfiction. Rarely do I think fiction or narrative nonfiction needs a competition section.
Ultimately the goal of competition is to show what’s out there. I think deleting something simply because it’s represented by the agent (or publisher) you’re pitching could do more harm than good. It gives the impression you don’t really know the market. The point of the competition section isn’t necessarily to show that there isn’t any competition, but to show that you know what the competition is and how your book is different and stands out from other titles. For this very reason you don’t want to bad-mouth the titles, but instead use them as a standard to make yours stand out even more.
And last, in case you’ve missed it, to better understand this question and what goes into a nonfiction book proposal, see my previous post on the subject.