Great Depression in the United States
The Great Depression began in August 1929, when the United States economy first went into an economic recession. Although the country spent two months with declining GDP, it was not until the Wall Street Crash in October 1929 that the effects of a declining economy were felt, and a major worldwide economic downturn ensued. The stock market crash marked the beginning of a decade of high unemployment, poverty, low profits, deflation, plunging farm incomes, and lost opportunities for economic growth as well as for personal advancement. Altogether, there was a general loss of confidence in the economic future.
Tariff
Milton Friedman held the opinion that the Smoot–Hawley tariff of 1930 did not cause the Great Depression, instead he blamed the lack of sufficient action on the part of the Federal Reserve. Douglas A. Irwin wrote: "most economists, both liberal and conservative, doubt that Smoot–Hawley played much of a role in the subsequent contraction".
Peter Temin, an economist at the Massachusetts Institute of Technology, explained that a tariff is an expansionary policy, like a devaluation as it diverts demand from foreign to home producers. He noted that exports were 7 percent of GNP in 1929, they fell by 1.5 percent of 1929 GNP in the next two years and the fall was offset by the increase in domestic demand from tariff. He concluded that contrary the popular argument, contractionary effect of the tariff was small.
William Bernstein wrote: "Between 1929 and 1932, real GDP fell 17 percent worldwide, and by 26 percent in the United States, but most economic historians now believe that only a miniscule part of that huge loss of both world GDP and the United States’ GDP can be ascribed to the tariff wars. .. At the time of Smoot-Hawley's passage, trade volume accounted for only about 9 percent of world economic output. Had all international trade been eliminated, and had no domestic use for the previously exported goods been found, world GDP would have fallen by the same amount — 9 percent. Between 1930 and 1933, worldwide trade volume fell off by one-third to one-half. Depending on how the falloff is measured, this computes to 3 to 5 percent of world GDP, and these losses were partially made up by more expensive domestic goods. Thus, the damage done could not possibly have exceeded 1 or 2 percent of world GDP — nowhere near the 17 percent falloff seen during the Great Depression... The inescapable conclusion: contrary to public perception, Smoot-Hawley did not cause, or even significantly deepen, the Great Depression.