We present tests of long-run monetary neutrality using an empirical framework that allows for the effects of real shocks on the long-run behavior of both output and monetary aggregates. Our findings support long-run monetary neutrality as a feature of the post World War II U.S, economy. We further find that permanent innovations in labor supply, as measured by working-age population, are a principal factor in the long-run movements in U.S, output and monetary aggregates.