News and the exchange rate revisited

This paper provides a theoretical framework to explain the increasing impact on the exchange rate of unanticipated money growth, with a stable short-term interest rate, and rising long-term rates. The assumptions of Purchasing Power Parity and Uncovered Interest Rate parity are relaxed. The appreciation of the currency is shown to be a direct result of the expected increase of future interest rates. A discussion is offered on the precise definition of the "surprise," under alternative assumptions. Heterogeneity of agents as regards exchange rate expectations, and the effect of long-term capital investments are also taken into account. It is shown that the surprise may have lagged effects on the exchange rate, and that its sign depends on the horizon of the portfolio investments (short or long). This paper has benefited from the comments of the participants at the 1996 International Atlantic Economic Conference in Paris. Financial support from the Instituto Valenciano de Investigaciones Económicas and the DGCYT under project PB94–1502 is acknowledged.