In Simon Raven’s novel Friends in Low Places (1965) there is a wonderful moment in which a bluff, no-nonsense character named the Marquess of Canteloupe remarks that any fool can make a profit: all you need is to find out what people want and make them pay a proper price for it. It is such a bracing observation, it always seemed to me, that it should have been inscribed on the walls of company boardrooms and quoted in economic primers as a means of demonstrating literature’s intimate relation to fiscal theory.The same idea seems to have occurred to Lucy Mangan, who devoted her highly amusing series (25-29 August) to a consideration of five literary texts that look to have some bearing on the question of profit and loss. The books were Douglas Adams’ The Hitchhiker’