I intend to break a record with this column, and publish what must surely be the FT’s longest ever correction. It’s not that I enjoy self-flagellation in public. But the manner of my error offers a lesson about economics as well as journalism.

First, the error. In the “Dear Economist” column, I recently described the research of Harold Hotelling. But I attributed to Hotelling an anecdote that is widely used but was probably never used by Hotelling himself.