A hand’s primary function, Elias Canetti writes in Crowds and Power, is as “a claw to grasp whole branches” while climbing; both hands partner in “grasping” and “letting go.” This is like trade, he argues: “one hand tenaciously holds on to the object with which it seeks to tempt the stranger” while the other “is stretched out in demand.” Trading, then, offers “profound and universal pleasure” as “a translation into nonphysical terms of one of the oldest movement patterns.”

Herodotus reports that after Cyrus the Great was warned by a Spartan herald not to tread further into Greek lands, the Persian king received a primer on Sparta, including an explanation of an agora, to inform his response. “I have never yet been afraid of any men,” he told the herald, “who have a set place in the middle of their city where they come together to cheat each other.”

A growing market for ejiao—a gelatin made from donkey hide believed by practitioners of traditional Chinese medicine to increase libido and slow aging—has led to a global trade of millions of donkey skins each year. Asses are often kidnapped from rural African villages, where their labor is valued highly, then taken to markets and slaughtered for export. “The donkeys,” said a sanctuary manager while visiting a market in Tanzania, “are very stressed.”

For Kid Nation, a reality show that aired in 2007, forty children went to stay in a New Mexico ghost town for forty days. They lived as laborers, cooks, merchants, or an upper class; many worked fourteen-hour days to earn buffalo nickels to spend on root beer. In the final episode, some participants raided the dry goods store. “It’s free,” said one kid, his mouth stuffed with gummy bears. Another raider was heard announcing, “There is a god.”

A seventeenth-century rabbinical decision tells of a German town in which wealthy Jewish households kept chickens, while poorer women secretly milked gentiles’ cows early in the morning to sell the purloined milk on the street. One time, some chicks hopped into a tub of milk left on a doorstep and drowned. “Each side suffered a financial loss,” the text reads. “One from the milk, the other from the drowned chicks.”