<P> William Bernstein writes "most economic historians now believe that only a minuscule part of that huge loss of both world GDP and the United States' GDP can be ascribed to the tariff wars "because trade was only nine percent of global output, not enough to account for the seventeen percent drop in GDP following the Crash . He thinks the damage done could not possibly have exceeded 2 percent of world GDP and tariff "didn't even significantly deepen the Great Depression ." (A Splendid Exchange: How Trade Shaped the World) </P> <P> According to Paul Krugman, "Protectionism was a result of the Depression, not a cause . Rising tariffs didn't even play a large role in the initial trade contraction"; "Where protectionism really mattered was in preventing a recovery in trade when production recovered". </P> <P> Peter Temin, explains a tariff is an expansionary policy (favourable to economic growth), like a devaluation as it diverts demand from foreign to home producers . He notes 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 concludes that contrary the popular argument, contractionary effect of the tariff was small . (Temin, P. 1989 . Lessons from the Great Depression, MIT Press, Cambridge, Mass) </P> <P> Nobel laureate Maurice Allais, thinks that tariff was rather helpful in the face of deregulation of competition in the global labor market and excessively loose credit prior to the Crash which, according to him, caused the crisis Financial and banking sectors . He notes higher trade barriers were partly a means to protect domestic demand from deflation and external disturbances . He observes domestic production in the major industrialized countries fell faster than international trade contracted; if contraction of foreign trade had been the cause of the Depression, he argues, the opposite should have occurred . So, the decline in trade between 1929 and 1933 was a consequence of the Depression, not a cause . Most of the trade contraction took place between January 1930 and July 1932, before the introduction of the majority of protectionist measures, excepting limited American measures applied in the summer of 1930 . It was the collapse of international liquidity that caused of the contraction of trade . </P>

How much did the gnp drop from 1929 to 1932