The scene is a rock-walled bakkal.

What is a bakkal?

It is a mom-and-pop shop. Only more.

In Turkey, it is the cheap, multi-hued soccer balls that hang in bulging net bags outside the doorway that readily identify a bakkal. We have been walking hundreds of miles across Anatolia using these bright navigational beacons. Why? Because a bakkal is an oasis. It offers cherry juice and bottles of potable water. A bakkal promises a spot of shade under the burning sun. The man or woman behind the counter dispenses travel directions—both physical and spiritual. Often, a glass of tea is offered. At minimum, there is a stool to sit on, to catch your breath, to rest.

But the bakkal in Yelkovan Koyü —a rural outpost forgotten by time—does not display any colorful soccer balls. It does not hum with an electric drink cooler. It is dim. Its counter is a raw plank. It is just a room, actually: the entrance to Omer Karadoğan’s home.

Village children appear in the store doorway, bent under heavy buckets of bulgur wheat or barley. They place the buckets on a battery-powered scale. Karadoğan squints at the weight. He scribbles figures on a scrap of paper. Then, he sweeps a hand over his manufactured wares: a regal gesture. The grain is used for barter.

“We are poor here,” Karadoğan acknowledges. He is a kind man. He himself is poor. “Not everybody has money in their pockets all the time,” he says. “I buy the grain and resell it in Kâhta for a small profit.”

In exchange, the Kurdish farmers in the village obtain soap or salt. Batteries or cigarettes. Notebooks and other schools supplies. There is a brisk trade in candy—in sweets.

“It is the children’s job to clean the grain,” Karadoğan explains. “This is their reward.”

Karadoğan trades at 60 cents worth of goods per kilogram of grain. A bucket of harvest buys a packet of Gofello cookies. Or a Çikobis chocolate bar. The faces of the boys and girls grow grave, intense, as they scan the dusty shelves to make their selections.

Adam Smith’s contempt for barter was total. He insisted on the supremacy of money; he derided barter as inefficient, quirky, impossible to regulate. Capitalists maintain that coined money probably was invented 2,600 years ago in Turkey precisely to overcome barter’s “double coincidence of wants”—the clumsy requirement that each partner must need the exact commodity they are trading.

This is not a problem in Yelkovan Koyü. Karadoğan wants the grain. The children want a sugar high. It is strangely compelling to watch, this gritty swap. An economic system from the Stone Age endures along the migration pathway of the first ancestors out of Africa. Even Mustafa Filiz, my urbane walking guide, is mesmerized.

What is the lesson?

“Walking shows me”—Filiz says, shaking his head in wonder, as we head out the store with our cash-bought junk food—“that I don’t know my own country.”