Intermediation

Money. The villagers are tired of bartering. The dairy farmer wants to buy corn, even when he does not have milk to trade, and the corn farmer wants to buy meat, even when the butcher does not want corn. So they decide that special gray stones that they can collect from a nearby riverbed will represent an abstract unit of value, called money. They reason that if everyone uses stones to represent value, then people can transact when they would like, rather than when both parties are willing and able to barter. The villagers have abstracted value.

Supply. The villagers picked special gray stones to be money because the stones were portable, durable, and most importantly hard to collect. The only way to get them was to walk an hour outside of town and spend all day sifting through the riverbed. Sometimes, a villager would do this and only find one or two special stones. And so like any other job—winemaking, farming, cobbling—the job of collecting stones was self-regulated by the value of the activity. If the villagers collected too many stones, like they did after a flood cut open a new seam of special stones in the riverbed, then the cost of goods would go up and the relative value of stones, and thus collecting them, would go down. Or vice versa. So the villagers decided that anyone could collect stones, just as anyone could forage for berries or dye cloth. More or fewer people would do it as demand changed.