<P> US imports decreased 66% from $4.4 billion (1929) to $1.5 billion (1933), and exports decreased 61% from $5.4 billion to $2.1 billion . GNP fell from $103.1 billion in 1929 to $75.8 billion in 1931 and bottomed out at $55.6 billion in 1933 . Imports from Europe decreased from a 1929 high of $1.3 billion to just $390 million during 1932, while US exports to Europe decreased from $2.3 billion in 1929 to $784 million in 1932 . Overall, world trade decreased by some 66% between 1929 and 1934 . </P> <P> Using panel data estimates of export and import equations for 17 countries, Jakob B. Madsen (2002) estimated the effects of increasing tariff and non-tariff trade barriers on worldwide trade during the period 1929--1932 . He concluded that real international trade contracted somewhere around 33% overall . His estimates of the impact of various factors included about 14% because of declining GNP in each country, 8% because of increases in tariff rates, 5% because of deflation - induced tariff increases, and 6% because of the imposition of non-tariff barriers . </P> <P> The new tariff imposed an effective tax rate of 60% on more than 3,200 products and materials imported into the United States, quadrupling previous tariff rates on individual items, but raising the average tariff rate to 19.2%, in line with average rates of that day . </P> <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>

How did the smoot-hawley tariff affect the american economy in the 1930's