I've been listening to a podcast called the Fall Of Rome by Patrick Wyman who goes into detail about the economy of the later Roman Empire. He details some of t

I've been listening to a podcast called the Fall Of Rome by Patrick Wyman who goes into detail about the economy of the later Roman Empire. He details some of the logistic systems the Romans had to bring food and other staples to the main cities of the Empire, which was subsidized by the Roman government. This allowed for shippers to then spend the rest of their shipping time on moving goods for profit. The merchant shipping basically broke even moving the goods for the government, after that any other jobs they could take were basically profit. This allowed for the shipping of items all over the Empire for very low prices. For example, common pottery that was made in large quantities in North Africa were shipped to Britain and even hundreds of miles inland into France. This would seem to indicate that it was cheaper to ship items from hundreds or thousands of km's away then they could be produced locally for a profit.