Economic ideas – ranging from new but unelaborated concepts through isolated propositions about causality, all the way to full-blown theories – arise in the highbrow part of the economics profession and then diffuse first within the profession and then sometimes outside it to journalists, bureaucrats, politicians, and other citizens. Eventually they trickle away into the sand, or maybe – if the moon is in the seventh house – have some influence on events. There is also a backflow of ideas from the World Out There to the economics profession, but those are hardly ever economic ideas. They are rather social beliefs, priorities, or ideological conceptions. It is not only the Supreme Court that reads the election returns. More important, economists are responsive to the same currents of opinion that affect other people.

The vehicles by which diffusion takes place and the routes traveled by those vehicles can be the object of interesting studies. In this paper I consider one aspect of the diffusion process relevant to the spread of ideas from economists to the lay public.

The transmission of complicated ideas is imperfect. By the time an economic idea reaches its ultimate destination it has been changed, distorted in one way or another. This is surely the case when an idea diffuses outside the profession. The average person-in-the-street has probably never heard of monetarism – even monetarism! Among the subset who have, the picture in their heads is very likely quite different from what the median-difficulty elementary textbook conveys, and certainly not what any professional economist would understand, let alone what a specialist in monetary macroeconomics would teach to graduate students.