A further idea I had. Sort of a minor overhaul of the way work works.
Workshops have two possible settings for how they are used:
-Personal
-Communal
Communal workshops work exactly the way workshops work now. They are entirely controlled by the player, and their output is entirely owned by the player (aka the government, the nobility, society, the will of the dwarves, the "force behind the throne", or however you like to think of the player as being).
Personal workshops are quite different. When a personal workshop is created, it is immediately claimed by the highest level dwarf of the relevant type. The workshop is now almost entirely in the hands of that dwarf, and that dwarf will devote most of his time to working in that workshop. When the dwarf would otherwise be idle, he would now go to his workshop and do various things - the two that immediately come to mind would be creating trinkets and other things that he likes, which are added to his personal possessions, given to a friend, or sold to a shop, and improving the workshop area to make it more pleasant to work in - engraving the walls, upgrading the workshop, maybe trying to obtain new tools or the like.
The player would still be able to order things built at personal workshops. When something is ordered built, the dwarf will finish whatever he is doing, construct the item, and then get paid for the item from the central treasury.
The core concept is that whatever a dwarf makes at his personal workshop, he owns.
Legendary dwarves would naturally demand their own personal workshop, and would throw a tantrum or go melancholy if they did not receive one, depending on their personalities. These demands could also be brought up to the Mayor, guild noble, or other noble, and that noble could mandate the construction of a workshop for the dwarf. Dwarves would always receive a happy thought if they had their own personal workshop ("He was pleased to work in his own [adjective] work area lately.") Dwarves would receive an unhappy thought if the workshop arrangements were less than adequate ("He was annoyed by the pretentious working arrangements of another lately./He was outraged to have to work in a communal workshop lately./He was unhappy at not having his own workshop lately.")
The idea is that, once the economy starts, the best way to go would be the personal workshop route. Additional incentives may be required - I don't know.
This sets up a cycle for goods and money. Crafty-type dwarves would make things at their personal workshops. They would then sell these things to shopkeeper dwarves. The shopkeeper dwarves would then sell things at their shops, and all dwarves would be able to buy things they liked at those shops. Money is injected into the system by ordering things built on the government's tab, and by lower-class hauler jobs and the like. The money circulates with the goods. Merchants would naturally get involved in this cycle - crafty-type dwarves would try to sell things to the merchants, and all dwarves would have the opportunity to buy trinkets and such from the merchants.
This is actually quite realistic for a simple economic model.
Important note: the system works best if the silly "credit" scheme is eliminated. Dwarves can only spend money that they actually physically possess, and they can only actually physically possess it by getting paid, ultimately by the treasury either through hauling jobs or ordered goods. This introduces both supply and demand and monetary management to the model - wages and prices would be set through a supply and demand process, which would naturally be affected by the amount of money that everyone has to spend, which would be a result of how much money the government has put into the system. If the government puts more money into the system, there is greater money supply and prices go up, and laborer dwarves become unhappy because they can't buy as many things. If the government puts less money into the system, there is less money supply and prices go down, and craftsdwarves and shopkeeper dwarves are unhappy because they can't earn as much.