Forward Speculation, Excess Returns, and Exchange Rate Variability: The Role of Risk Premiums

The paper reconsiders the unbiasedness hypothesis in the foreign exchange market. Within the context of a conventional model of exchange rates, risk premium shocks are constrained to have no permanent effects on the spot rate. Using monthly data from the post-floating period, the paper estimates risk premiums for the dollar rates of the yen, mark, and pound. Risk premium innovations seem to explain a modest proportion of short-term variability of exchange rate changes and excess returns. However, risk premiums may explain serial correlations in excess returns.