This paper offers a reappraisal of the inflation–unemployment tradeoff, based on frictional
growth, describing the interplay between nominal frictions and money growth. When the money
supply grows in the presence of price inertia (due to staggered wage contracts with time
discounting), the price adjustments to each successive change in the money supply are never able to work themselves out fully. In this context, temporary nominal rigidities let monetary policy have permanent real effects. Although our theory contains no money illusion, no permanent nominal
rigidities, and no departure from rational expectations, there is a long-run inflation–unemployment tradeoff. Our empirical analysis suggests that this Phillips curve may be reasonably flat. We show that the persistence of inflation and unemployment, in response to monetary policy shocks, is related to the slope of the long-run Phillips curve.