From your description, it seems clear that the book's Caplan is supposed to mock Robin Hanson, or possibly a combination of various GMU economists, since Bryan Caplan is one of Hanson's colleagues there. This also fits with an exaggerated view of Hanson and Yudkowsky disagreeing about hard takeoff and the need for Friendliness.
From a review of Greg Egan's new book, Zendegi:
(Original pointer via Kobayashi; Risto Saarelma found the review. I thought this was worthy of a separate thread.)