Economist Frédéric Bastiat published a parodic open letter to French parliament in 1845 that imagined the national lighting industry lobbying for a law to black out all windows in response to the “ruinous competition” of the sun, which was “flooding the domestic market.” “Be logical,” the letter concludes, “for as long as you ban, as you do, foreign coal, iron, wheat, and textiles, in proportion as their price approaches zero, how inconsistent it would be to admit the light of the sun, whose price is zero all day long!”

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.”

The head female of a paper-wasp nest allows others to occupy space in her home—so long as they help raise her offspring. The labor market is, however, elastic: if other nests nearby have childcare needs, she maintains a lower work requirement from her “helper” wasps.

One of the most extensive surviving archives of Old Babylonian writing consists of letters sent to Ea-nasir, an eighteenth-century-bc copper merchant from Ur. “You have offered bad ingots to my messenger,” complained one trading partner. “Who am I that you are treating me in this manner?” Another customer appears repeatedly in the archive, each time inquiring about a missing copper shipment. “Do you not know,” he wrote in his third missive, “how tired I am?”

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.”