The rise of cities and kingdoms and the improvement in transport infrastructure brought about new opportunities for specialization. Densely populated cities provided full-time employment not just for professional shoemakers and doctors, but also for carpenters, priests, soldiers, and lawyers. Villages that gained a reputation for producing really good wine, olive oil, or ceramics discovered that it was worth their while to specialize nearly exclusively in that product and trade it with other settlements for all the other goods they needed. This made a lot of sense. Climates and soils differ, so why drink mediocre wine from your backyard if you can buy a smoother variety from a place whose soil and climate are much better suited to grapevines? If the clay in your backyard makes stronger and prettier pots, then you can make an exchange. Furthermore, full-time specialist vintners and potters, not to mention doctors and lawyers, can hone their expertise to the benefit of all. But specialization created a problem: how do you manage the exchange of goods between the specialists?🏁

The rise of cities and kingdoms and the improvement in transport infrastructure brought about new opportunities for specialization. Densely populated cities provided full-time employment not just for professional shoemakers and doctors, but also for carpenters, priests, soldiers, and lawyers. Villages that gained a reputation for producing really good wine, olive oil, or ceramics discovered that it was worth their while to specialize nearly exclusively in that product and trade it with other settlements for all the other goods they needed. This made a lot of sense. Climates and soils differ, so why drink mediocre wine from your backyard if you can buy a smoother variety from a place whose soil and climate are much better suited to grapevines? If the clay in your backyard makes stronger and prettier pots, then you can make an exchange. Furthermore, full-time specialist vintners and potters, not to mention doctors and lawyers, can hone their expertise to the benefit of all. But specialization created a problem: how do you manage the exchange of goods between the specialists?🏁