Low tariff rates have been the norm for the United States and most other major economies since the end of World War II, but that hasn’t always been the case. From the second half of the 19th century to the early 20th, the US had very restrictive tariffs.
One key lesson is that high tariffs, once they’re in place, are very hard to dislodge, owing to vested interests and the need for unified control over government.
In contrast to most issues, US presidents can enact sweeping changes on trade without congressional approval. We estimate that Donald Trump’s proposed tariff hikes would subtract 1.9% from the long-run level of US real GDP.
Still, we think it’s more likely than not that Trump would back down from the threatened tariffs, particularly the 10% uniform hike. This leads to a probability-weighted impact of 0.13%.