Preferred Risk by Frederick Pohl and Lester del Rey

Does for the insurance business what Pohl and Kornbluth's The Space Merchants did for the advertising world.

As explained in the two afterwords (one by each author), Preferred Risk yoked together two writers with drastically different writing habits to expand a novelette into a novel. As Pohl says, at the end he and del Rey may not have had a great novel but they had a finished novel.