Sources of Purchasing Power Disparities between the G3 Economies

Recent theoretical and empirical research in international macroeconomics has rediscovered the problem of purchasing power parity (PPP). Empirically, PPP is a bad approximation of both the short-term and medium-term properties of the data. Economists have had difficulties in explaining the persistent misalignments of real exchange rates, but new empirical research by Clarida and Galí (1995), Carnegie Rochester Conference Series on Public Policy, Vol. 41 suggested that much of these real exchange rate movements are due to relative demand shocks. The present paper challenges this view by using an extended version of their structural vector autoregressive (SVAR) model in order to identify a larger number of real shocks (labor supply, productivity, and aggregate demand) and nominal shocks (money demand and money supply). It is found that while some of their results go through in our extended framework, there is serious doubt with respect to the appropriateness of labeling those shocks which drive real exchange rates as aggregate demand disturbances.J. Japan Int. Econ.December 1997,11(4), pp. 548–583. Universität Bonn, Lennéstrasse 43, 53113 Bonn, Germany and CEPR.