During a televised debate between Congressman Ron Paul and Nobel Laureate Paul Krugman, Congressman Paul pointed to inflation under Diocletian as a reason to be concerned about expansion of the money supply today. Prof. Krugman disagrees, although he admits to little knowledge of ancient history, and in a subsequent post discusses the difficulty of talking about the "zero lower bound" when the numerical system has no zero. In Slate, Matthew Yglesias provides a literature summary on the topic.