This interesting article
attempts to explain the economics of Azeroth in terms of real life economic theory. As players, I'm sure we can all poke holes in this theoretical view of our favorite game, or perhaps find the lack of game knowledge frustrating. For example... Goods rarely cost less in the neutral auction house (though sometimes lower prices will reflect lower prices on the Alliance or Horde side - but usually neutral prices are jacked up to the highest possible profit rate), due to the higher cut the Goblins take out of the transaction. Trade-skill items are of less economic importance than seems to be placed on them - very few craftable items being desirable, long-term, over bind on pickup drops found in dungeons. And it does not consider Blizzard's continued efforts to rid the game of gold farmers, which has an ongoing (though variable) impact on the available supply of gold in the economy. However, it is always interesting to see how real economic theory can apply to a virtual game world, and I would say the article is worth a read.
Update: The comments below may well shed more light on the subject than the initial article - so read on!