One may wonder why I am applying this ideology to themepark MMOs and not Sandbox MMOs (true sandbox). That’s because in a sandbox MMO there are fewer quests and practically no dailies, and money generation is much slower or perhaps there are more faucets that money can exit through. But in a sandbox MMO player activity doesn’t change from the beginning to the end. The end game is pretty much the same as the beginning of the game.
Activities are repeatable but are not usually in the form of quests. Also just about all activities for gear are purchased from other players through the use of the Auction House and not from other sources such as drops or npc’s. This allows money to exit the game in the form of taxes. Finally, in some sandbox games the production of goods are even taxed to increase the flow of money leaving the economy
As a result, in themepark mmo’s money activity is fairly active in the beginning. Money is leaving just as fast as it’s being created. However, as the MMO matures and player activity shifts, the creation of money outweighs the destruction money, resulting in the inevitable rise in inflation. Usually it takes an expansion and a level increase to cause player activity to re-balance creation and destruction of money.