How Did the Inca Empire Have a Stable Economy without Markets?

IO9 asks the above question. I'll answer it with another question: Who says their economy was stable?

The Inca regime became an empire less than a century before it was overthrown by Spanish adventurers … and was in the middle of a civil war when the Spanish arrived. Maybe it was about to fall apart on its own. We don't know what kind of shortages they had but, judging by present-day attempts at evading markets, they almost certainly had shortages.

They didn't have a written language, so we cannot read any equivalent of Dr. Zhivago or The Gulag Archipelago. What little we do know comes from Spanish sources. The Spanish regime was almost as fascist as the Incas and might not have been inclined to preserve records of a similar failure.