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 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.