[Hermann the Cherusker]

At a time when international trade accounted for 1% of the GDP, and when the US was self-sufficient in ferro-metals, heavy and rare earth metals and natural resources like oil and timber, it is incredibly difficult to believe that Smoot-Hawley had anything to do with the 33% decline in GDP experienced from 1929 to 1933.

1% was then and is still <<<<< 33%

[CobaltBlue]

The Great Depression, which was a world-wide event, was multi-factorial in causation. It's a very great mistake to focus only on one cause.

One problem with tariffs that you may not realize is that foreigners needed American money in order to pay off loans of money borrowed from Americans, but were unable to get American money because they were unable to sell goods and services in America. This caused them to default on their loans, which was bad for the Americans who loaned them the money. Tariffs enrich one segment of society at the expense of others.

Think of it as raising taxes during a recession. That's just plain dumb, we all know that the best thing to do in a recession is cut taxes.

[CobaltBlue]

BTW, gross income from exports was closer to 6% of US GDP in 1929, and gross income from imports was closer to 5%. When you net them out, the net is less than 1%, but netting them out I think is misleading in terms of economic value to the economy as a whole.

GDP only measures expenditures. It can't measure value added.