To this end, he then explored the implications of neo-Fisherian ideas that include the core idea that an interest rate peg, in some circumstances, can be stable. In this context, “ZIRP, far from being a harbinger of runaway inflation, would instead dictate medium- and long-term inflation outcomes,” he said. (For additional discussion, see Bullard’s speech on Nov. 12, 2015, “Permazero.”)