The Relative Impact of Fiscal versus Monetary Actions on Output: A Vector Autoregressive (VAR) Approach

The seminal work of Andersen and Jordan [1] on the relative importance of fiscal and monetary policy for output stabilization (the St. Louisequation) caused many debates among economists for a long period. They run a single equation model testing the relative importance of monetaryversus fiscal policy on nominal GNP and concluded that monetary policy is effective and fiscal policy is ineffective on output stabilization. Thisfinding attracted a wide range of criticisms and debates mainly due to possible endogeneity between policies and economic activity, andmisspecification of the model. This study takes the St. Louis equation seriously. Our main concern is that, the economic activity is represented bynominal output and to our surprise; the impact of monetary or fiscal policies on prices has not been given any attention. All such models withnominal output as the dependent variable could not address the question of how policy induced changes are split between a change in real outputand a change in prices. This paper investigates the relative impact of monetary and fiscal policies on the U.S. real economic activity, using quarterlydata between 1959:I and 2010:II. We employ Granger causality tests and Vector Autoregressive (VAR) models. The VAR methodology also helps inresolving the issue of endogeneity between policies and output. The results from both models indicate that monetary policy is relatively betterthan fiscal policy in affecting the real output. No other study attempted to investigate the relative impact of monetary and fiscal policy actions onreal output in the St. Louis framework as well as the econometric approach used in this paper to address the issue.