What is the greenback's sustainable value?

CAMBRIDGE, Mass. — How much further will the dollar fall? Or has it already fallen so far that it will now start to move back to a higher level?

For travelers to the United States from Europe or Asia, U.S. prices are dramatically lower than at home. A hotel room or dinner in New York seems a bargain when compared to prices in London, Paris, or Tokyo. And shoppers from abroad are loading up on a wide range of products before heading home.

But, despite this very tangible evidence, it would be wrong to conclude that U.S. goods are now so cheap at the existing exchange rate that the dollar must rise from its current level. Although the goods and services that travelers buy may cost less in the U.S. than abroad, the overall price of American products is still too high to erase the enormous trade imbalance between the U.S. and the rest of the world.