David Ricardo’s theory of comparative advantage is counterintuitive, and a lot of people struggle with it. Most of us can see why free trade works in the interest of competitive countries. How, though, can it be in the interest of less efficient places? Why wouldn’t all the jobs go to the more productive trading partner?

For years, I struggled to convince skeptics of the theory, which relies on a bit of math. Then I stumbled upon a short sketch by the comedian Dave Chappelle. Satirizing President Donald Trump’s obsession with bringing Chinese jobs to the United States, Chappelle asks, “For what, n****r? So iPhones can be $9000? Leave that job in China where it belongs, none of us wanna work that hard!” Warming to his theme, he gives as pithy summary of the case for free trade as you will hear: “I wanna wear Nikes, I don’t wanna make them s***s!”