<P> Unemployment was at 8% in 1930 when the Smoot--Hawley tariff was passed, but the new law failed to lower it . The rate jumped to 16% in 1931, and 25% in 1932--33 . There is some contention about whether this can necessarily be attributed to the tariff, however . It was not until World War II, during which "the American economy expanded at an unprecedented rate", that unemployment fell below 1930s levels . </P> <P> Imports during 1929 were only 4.2% of the United States' GNP and exports were only 5.0% . Monetarists, such as Milton Friedman, who emphasize the central role of the money supply in causing the depression, note that the Smoot--Hawley Act only had a contributory effect on the entire U.S. economy . </P> <P> The 1932 Democratic campaign platform pledged to lower tariffs . After winning the election, President Franklin Delano Roosevelt and the now - Democratic Congress passed Reciprocal Trade Agreements Act of 1934 . This act allowed the President to negotiate tariff reductions on a bilateral basis, and also treated such a tariff agreement as regular legislation, requiring a majority, rather than as a treaty requiring a two - thirds vote . This was one of the core components of the trade negotiating framework that developed after World War II . The tit - for - tat responses of other countries were understood to have contributed to a sharp reduction of trade in the 1930s . After World War II this understanding supported a push towards multi-lateral trading agreements that would prevent similar situations in the future . While the Bretton Woods Agreement of 1944 focused on foreign exchange and did not directly address tariffs, those involved wanted a similar framework for international trade . President Harry S. Truman launched this process in December 1945 with negotiations for the creation of a proposed International Trade Organization (ITO). As it happened, separate negotiations on the General Agreement on Tariffs and Trade (GATT) moved more quickly, with an agreement signed in October 1947; in the end, the US never signed the ITO agreement . Adding a multilateral "most - favored - nation" component to that of reciprocity, the GATT served as a framework for the gradual reduction of tariffs over the subsequent half century . </P> <P> Post--World War II changes to the Smoot--Hawley tariffs reflected a general tendency of the United States to reduce its tariff levels unilaterally while its trading partners retained their high levels . The American Tariff League Study of 1951 compared the free and dutiable tariff rates of 43 countries . It found that only seven nations had a lower tariff level than the US (5.1%), while eleven nations had free and dutiable tariff rates higher than the Smoot--Hawley peak of 19.8% including the United Kingdom (25.6%). The 43 - country average was 14.4% which was 0.9% higher than the US level of 1929 demonstrating that few nations were reciprocating in reducing their levels as the U.S. reduced its own . </P>

The general agreement on tariffs and trade (gatt) was part of american attempts to increase