By Annalee Newitz, io9.com, Jan 3, 2012
In the fifteenth and sixteenth centuries, the Inca Empire was the largest South America had ever known. Centered in Peru, it stretched across the Andes’ mountain tops and down to the shoreline, incorporating lands from today’s Colombia, Chile, Bolivia, Ecuador, Argentina and Peru – all connected by a vast highway system whose complexity rivaled any in the Old World. Rich in foodstuffs, textiles, gold, and coca, the Inca were masters of city building but nevertheless had no money. In fact, they had no marketplaces at all.
The Inca Empire may be the only advanced civilization in history to have no class of traders, and no commerce of any kind within its boundaries. How did they do it?