Sebastian Giesen

The Quantity Theory Revisited: A New Structural Approach

While the long run relation between money and inflation is well established, empirical evidence on the adjustment to the long run equilibrium is very heterogeneous. In this paper, we show that the development of US consumer price inflation between 1960Q1 and 2005Q4 is strongly driven by money overhang. To this end, we use a multivariate state space framework that substantially expands the traditional vector error correction approach. This approach allows us to estimate the persistent components of velocity and GDP. A sign restriction approach is subsequently used to identify the structural shocks to the signal equations of the state space model that explain money growth, inflation, and GDP growth. We also account for the possibility that measurement error exhibited by simple-sum monetary aggregates causes the consequences of monetary shocks to be improperly identified by using a Divisia monetary aggregate. Our findings suggest that when the money is measured using a reputable index number, the quantity theory holds for the United States.

A note on the hidden risk of inflation

The continued expansionary policy of the Federal Reserve gives rise to speculation whether the Fed will be able to maintain price stability in the coming decades. Most of the scientific work relating money to prices relies on broad monetary aggregates (i.e. M2 for the United States). In our paper, we argue that this view falls short. The historically unique monetary expansion has not yet fully reached M2. Using a cointegration approach, we aim to show the hidden risks for the future development of M2 and correspondingly prices. In a simulation analysis we show that even if the multiplier remains substantially below its pre-crisis level, M2 will exceed its current growth path with a probability of 95%.