It might be old and unfashionable, but investors are ignoring surprisingly juicy yields. : It is hard to get a man to understand something, wrote Upton Sinclair, an American novelist, when his salary depends on not understanding it. Hard, but not impossible: just look at those paid to promote Britain’s stockmarket. Bankers and stock-exchange bosses have an interest in declaring it an excellent place to list new, exciting businesses, as do politicians. Yet deep down they seem keenly aware that it is doomed.