For pranksters of a certain age, Fraser Smeaton is a hero. With his brother, Ali, and former roommate, Gregor Lawson, the Scottish business leader is cofounder of MorphCostumes. The U.K. company launched a twist on the zentai full-body spandex suit in 2009 and spawned a legion of viral videos. When a Gap store on Fifth Avenue was “morphed” by a band of improv-artists in 2018, the police had to be called. The accompanying video received millions of views.

MorphCostumes’ biggest market is America, particularly around Halloween, when children from Detroit to West Palm Beach like nothing better than ghost outfits and fake blood. Smeaton—who runs the company from its Edinburgh headquarters—is now an expert in global tariff policy and the negative impact of economic volatility and barriers to trade. The President should give him a call.

MorphCostumes is a Main Street example of tariff effects. It makes its costumes in China, which has a 30-year start on the rest of the world in the business of clothing production. Moving production elsewhere is prohibitively expensive.

Since Donald Trump entered the White House for the second time, the U.S. import taxes faced by Morph, which supplies Walmart and Target, have lurched wildly—from zero tariffs to 20% tariffs to 50% tariffs, before briefly flirting with 145% tariffs. The figure fell back to 20%, before the Supreme Court intervention last week ruled the tariffs illegal, which brought them back down to zero. The president then announced a new 10% tariff, although there is some confusion about whether he actually means 15%.