Creating balanced in-game economies (Gamasutra)

Interesting piece:  http://www.gamasutra.com/php-bin/news_index.php?story=22002

An excerpt:

…the early days of Ultima Online were infamous for the game’s wild and chaotic economy. Zachary Booth Simpson wrote a classic analysis of UO in 1999, detailing some of the more notable problems experienced at launch:

- the crafting system encouraged massive over-production by rewarding players for each item produced
- this over-production led to hyper-inflation as NPC shopkeepers printed money on demand to buy the worthless items
- players used vendors as unlimited safety deposit boxes by setting the prices for their own goods far above market value
- item hoarding by players forced the team to abandon the closed-loop economy as the world began to empty out of goods
- player cartels (including one from a rival game company!) cornered the market on magical Reagents, preventing average users from casting spells