Third, the composition of trade matters to the nation's prosperity.

But the activists part company with traditional free traders on whether the composition of trade should be a critical government concern.

They sought a highly interventionist agenda, using taxes on trade to manipulate the balance of trade or commodity composition of trade in favor of the home country.

"The lowering of tariffs through Nafta has not had a significant impact on the rate of growth of imports or exports between Mexico and the United States, or on the composition of trade between sectors recently liberalized by Nafta and those sectors still awaiting liberalization," the study said.

To the Editor: In his Op-Ed article "It's Clinton's Turn to Bargain With Japan" (April 15), Clyde Prestowitz identifies the composition of trade between the United States and Japan as the area of most concern in U.S.-Japan trade relations.