When Donald Trump began yesterday’s announcement of the White House’s latest trade policy brandishing a novelty-sized cardboard sign labeled “Reciprocal Tariffs,” the immediate and nearly unanimous response was bafflement. Trump slapped a 10 percent baseline tariff on all imports into the US, including from uninhabited islands, plus absurdly high rates on specific countries, supposedly based on “tariffs charged to the USA” — which didn’t match up to other, non-cardboard-sign-based estimates. Stock markets have plummeted and consumers are facing down sharp price hikes on potentially almost everything they buy.

Where did these numbers come from? Apparently, an oversimplified calculation that several major AI chatbots happen to recommend.

Economist James Surowiecki quickly reverse-engineered a possible explanation for the tariff pricing. He found you could recreate each of the White House’s numbers by simply taking a given country’s trade deficit with the US and dividing it by their total exports to the US. Halve that number, and you get a ready-to-use “discounted reciprocal tariff.” The White House objected to this claim and published the formula it says that it used, but as Politico points out, the formula looks like a dressed-up version of Surowiecki’s method.

In case you weren’t sure, Surowiecki calls this approach “extraordinary nonsense.” So why did Trump’s team use it? Well, like plenty of people who’ve realized their homework is due in three hours’ time, it seems like they may have been tempted by AI.