The relationship between stock returns and inflation depends on both the monetary policy regime and the relative importance of demand and supply shocks. A simple analytical framework by which to empirically examine the relative importance of these two factors is developed in this paper. Our findings indicate that the positive relationship between stock returns and inflation in the 1930s is mainly due to strongly pro-cyclical monetary policy, while the strong negative relationship of stock returns and inflation during the period of 1952-1974 is largely caused by supply shocks that were relatively more important in that period. Our results are broadly consistent with the general economic literature on monetary policy and stagflation. (C) 2005 Elsevier Inc. All rights reserved.