Implications of Endogenous Money Growth for Some Tests of Superneutrality and the Fisher Effect

Superneutrality of money and the Fisher Effect are well-known theoretical propositions. Empirical tests of long-run versions of these hypotheses have sometimes been done by estimating how a variable responds to a permanent shock to inflation. Substituting inflation for money growth in a test for superneutrality is motivated by the widely-accepted Monetarist precept that “inflation is everywhere and always a monetary phenomenon.” Use of permanent shocks to inflation and money growth for testing such hypotheses has declined, in part because permanent movements in these variables have an endogenous component and so estimates are biased. But the sign of the bias may be determined using credible qualitative assumptions about the effects of structural shocks on variables. These results are used to re-examine multi-country findings from two di˙erent structural VAR models that estimate the effects of permanent inflation shocks. One finding is rejection of superneutrality for output in favor of a long-run positive output effect from permanently higher money growth. The second is rejection of the Fisher Effect in favor of nominal rates moving less than one-for-one in the long run with inflation. Both rejections are shown to be robust to endogenous money growth bias under a wide range of plausible structural assumptions. These results for real interest rates and output provide evidence in support of structural models which give rise to a Mundell-Tobin effect.