Monetary Policy in a World Where Money (Also) Matters

While the long-run relation between money and inflation as predicted by the quantity theory is well established, empirical studies of the short-run adjustment process have been inconclusive at best. The literature regarding the validity of the quantity theory within a given economy is mixed. Previous research has found support for quantity theory within a given economy by combining the P-Star, the structural VAR and the monetary aggregation literature. However, these models lack precise modelling of the short-run dynamics by ignoring interest rates as the main policy instrument. Contrarily, most New Keynesian approaches, while excellently modeling the short-run dynamics transmitted through interest rates, ignore the role of money and thus the potential mid- and long-run effects of monetary policy. We propose a parsimonious and fairly unrestrictive econometric model that allows a detailed look into the dynamics of a monetary policy shock by accounting for changes in economic equilibria, such as potential output and money demand, in a framework that allows for both monetarist and New Keynesian transmission mechanisms, while also considering the Barnett critique. While we confirm most New Keynesian findings concerning the short-run dynamics, we also find strong evidence for a substantial role of the quantity of money for price movements.