Modern theories of inflation incorporate a vertical long-run Phillips curve and are usually estimated using techniques that ignore the non-stationary behaviour of inflation. Consequently, the estimates obtained are imprecise and unable to test the veracity of a vertical long-run Phillips curve....

‘Modern’ Phillips curve theories predict inflation is an integrated, or near integrated, process. However, inflation appears bounded above and below in developed economies and so cannot be ‘truly’ integrated and more likely stationary around a shifting mean. If agents believe inflation...

This paper argues that because United States inflation has been non-stationary over the past five decades the vast body of empirical research that proceeds without adequately accounting for the non-stationarity in the data is invalid. Using 50 years of United States inflation data the standard...