Here’s How Trump Calculated His Tariffs—and It’s Ridiculous

The Trump administration seems to have destroyed global economies overnight while misunderstanding basic economics.

In the wake of Donald Trump’s tariff announcement Wednesday, former New Yorker financial writer James Surowiecki pointed out that a column on Trump’s tariff sheet labeled “tariffs charged to the U.S.A.” was likely founded on bad math.

“They didn’t actually calculate tariff rates + non-tariff barriers, as they say they did. Instead, for every country, they just took our...