He signed his name and official title of Ukyo no Daibu (Right City Commissioner) on the first page of the book, and if it is true, although there is no record of his being appointed as Ukyo no Daibu, it would be his final title, which is the only reason why many people suppose that the work was written in his later years.
冒頭の作者署名に右京大夫と官名が記されており、明衡が右京大夫に任官した記録は他にないが、事実とすればこれが彼の極官であったことから、晩年の作であろうとする見解が多いだけである。