The results of Sarkar and Singer (1991) on the trends in the relative unit values of the manufactured exports of developing countries are sensitive to the choice of end-year and to fluctuations in the unit values of US exports relative to those of the rest of the world. The relative unit values of US exports are highly correlated with movements in the US real exchange rate, and there is some evidence to suggest that Sarkar and Singer's findings primarily reflect changes in the real exchange rates of developing countries.