On the Instability of Variance Decompositions of the Real Exchange Rate Across Exchange-Rate-Regimes : Evidence from Mexico and the United States

Variance decompositions of the Mexico-United States real exchange rate are examined using monthly data on consumer prices and the nominal exchange rate for the period January, 1969 to February, 2000. The results show that the robust result found in industrial-country data that most of the variation of the real exchange rate is due to fluctuations in prices of tradable goods and nominal exchange rates holds only in periods in which Mexico was not under a regime of exchange-rate management. In periods in the sample in which Mexico had a managed exchange-rate regime, the variability of prices of non-tradable goods relative to tradable goods accounts for up to 70 percent of the variability of the peso-dollar real exchange rate