Revlgking. I must confess I only did stage 1 economics at university but we learned that money is simply a medium of exchange. Smokes serve the same purpose in prison (so I'm told). Money wasn't invented until about 600 BC, by the Lydians I think. But surely no-one would deny the ancient Egyptians and Mesopotamians had an economy. Goods were traded for thousands of miles (kilometres if you prefer). In pre-European Australia artifacts also made it huge distances from their place of origin. This exchange over huge distances makes its appearance in the Upper Paleolithic. They mightn't have had a stock exchange but I'd have to call it an economy. Perhaps we would be better able to study modern economies if we keep all this in mind.