The Friedman's and Mishkin's Hypotheses (Re)Considered

This paper o¤ers to investigate both the Friedman's and Mishkin's hypotheses on the consequences of inflation on output growth. To this end, we first base these hypotheses in a unified framework. Second, in an empirical work based on OECD countries, we distinguish between short-medium and long run and between headline and core inflation. We get two main results. First, nominal uncertainty and inflation are positively linked. Second, headline inflation negatively Granger causes out- put gap (US, Japan, France) but has no effect on potential output growth (US excepted) whereas core inflation impacts potential output growth (UK, Germany) but not output gap (US excepted).