There is a lot in a name. This column looks at the ideas that are wrongly attributed to Irving Fisher and David Ricardo. Incorrect attribution can be more dangerous than it seems, and the prestigious names of Ricardo and Fisher have been used to justify inattentive fiscal and monetary policies. Fisher, for instance, understood that under certain circumstances, including perfect foresight, real interest rates might be immune to changes in inflation, at least over the long haul. But he rejected the premises needed to erect such a theory.