As a repeat of what happened during the Great Depression, US imposes import duties on China:

The House of Representatives on Tuesday voted 370-39 to ensure the United States can impose duties on subsidized goods from China and Vietnam, a move the White House said was needed to protect American jobs.

The bill, which overturns a recent court ruling, now goes to President Barack Obama to sign it into law. The Senate passed the legislation on Monday, in a rare display of bipartisan cooperation, just days after it was introduced.

“China distorts the free market by giving enormous subsidies to its producers and exporters, and our companies and workers should not be expected to compete against the deep pockets of the Chinese government,” House Ways and Means Committee Chairman Dave Camp, a Michigan Republican, said during debate.

http://www.reuters.com/article/2012/03/06/us-usa-china-trade-idUSTRE8251FA20120306

The US Senate has voted to uphold Washington’s ability to impose duties on subsidised goods from China and Vietnam.

This follows a US court ruling against the practice. The House of Representatives is expected to pass the bill, which will then go to President Barack Obama to sign into law.

Opponents say the measure escalates tensions between the two countries.

Those who support the bill say it protects thousands of American jobs.

“By passing this bill, we’re backing American workers and businesses in the fight against China’s unfair trade practices,” said Senate finance committee chairman Max Baucus in a statement.
http://www.bbc.co.uk/news/business-17267592

The Tariff Act of 1930 (P.L. 71-361), otherwise known as the Smoot-Hawley Tariff or Hawley-Smoot Tariff,^[1] was an act, sponsored by Senator Reed Smoot and Representative Willis C. Hawley, and signed into law on June 17, 1930, that raised U.S. tariffs on over 20,000 imported goods to record levels.^[2]

The overall level tariffs under the Tariff were the second-highest in U.S. history, exceeded by a small margin only by the Tariff of 1828.^[3] The act, and the ensuing retaliatory tariffs by U.S. trading partners, reduced American exports and imports by more than half.

Economic effects

At first, the tariff seemed to be a success. According to historian Robert Sobel, “Factory payrolls, construction contracts, and industrial production all increased sharply.” However, larger economic problems loomed in the guise of weak banks. When the Creditanstalt of Austria failed in 1931, the global deficiencies of the Smoot-Hawley Tariff became apparent.^[12]

U.S. imports decreased 66% from US$4.4 billion (1929) to US$1.5 billion (1933), and exports decreased 61% from US$5.4 billion to US$2.1 billion, both decreases much more than the 50% decrease of the GDP. Thus exports minus imports which is the GDP formula declined from 1 billion to 600 million while GDP was 58.9 billion, a trivial effect on GDP of about 2/3 of 1%.

According to government statistics, U.S. imports from Europe decreased from a 1929 high of $1,334 million to just $390 million during 1932, while U.S. exports to Europe decreased from $2,341 million in 1929 to $784 million in 1932. Overall, world trade decreased by some 66% between 1929 and 1934.^[14]

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.

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.

Although the tariff act was passed after the stock-market crash of 1929, some economic historians consider the political discussion leading up to the passing of the act a factor in causing the crash, the recession that began in late 1929, or both, and its eventual passage a factor in deepening the Great Depression.^[15] Unemployment was at 7.8% in 1930 when the Smoot-Hawley tariff was passed, but it jumped to 16.3% in 1931, 24.9% in 1932, and 25.1% in 1933.^[16]

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.^[17]
http://en.wikipedia.org/wiki/Smoot%E2%80%93Hawley_Tariff_Act