A year ago, there was some debate (e.g., S. Kopits) whether tariffs on US soybeans would have any impact on US soybean exports — that is since soybeans were highly substitutable, US soybean exports would be redistributed w/o an impact on prices.
From Deutsche Bank today:
As of July, year-to-date cumulative US exports of soybeans were down roughly 11.4
million metric tons compared to the same period last year but soybean exports to
China were down around 17.4 million metric tons.
DB Figure 2 says it all.
Source: Ryan, et al. “Trade Update: (Soy)bean counting,” Deutsche Bank, 13 August 2019.
Had soybeans been perfectly fungible, then US exports would’ve been pretty flat given global exports over the previous 12 months (see page 1, Oilseeds: World Trade and Markets, August 2019).