I know the new release is soon, and you're all burning with one single question: What does some guy on the internet think should be changed with the economy? Never fear, I am here to sate your curiousity.
Let's revisit how the economy works. I'm not certain, but I surmise:
1) The State is considered to own everything on the map.
2) The State issues imaginary payments to dwarves for transforming resources into higher valued resources. Nobles would prefer if those imaginary resources were represented by physical markers like coins, but they'll settle for bookkeeping if they have to.
3) Shopkeepers redistribute wealth by purchasing items from the State and selling them at markup to individual dwarves. Shops periodically issue low priority shopping tasks (ie, tasks that flash relatively infrequently).
4) The State owns all space as well. It rents private spaces to individual dwarves for their needs, but provides public assistance to dwarves in need via barracks. I am totally clueless about how dwarves (or the State) choose individual tenants, but when tenants cannot pay, they are evicted.
As a gamer, I'm happy with this general model. I don't expect modern capitalism, and the transformation from pre-economy communalism seems appropriate. However, I think that the economy should be something seen as a benefit, not as a curse. I think the economy should free the gamer from micromanagement of dwarf happiness (and of more, as you might agree if you bother to read what should be a mammoth of a post on the second page of an old thread.) I'm dividing this into easy, hard, and long-term implementations.
EASY:
Shops flash management tasks that can only be accepted by the individual shopkeeper. In each management task, the shopkeeper visits the shop and reduces prices on any items that have been unsold since the last management task. This price reduction works as a noble price adjustment: it affects all shops. It also works on two levels: the level of materials, and the level of object. If a shopkeeper revisits a shop to find an onyx ring unsold, it will reduce the price of onyx items by a certain percentage, and it will reduce the price of rings by a certain percentage. The exact percentages require a bit of playtesting, but any low value will do-- lower adjustments will just slow adjustment. They should be modifiable values in init. If the shopkeeper returns to find all items unsold, the shopkeeper should proceed to refuse the cheapest item placed in the shop. If the shopkeeper returns to find an item sold, it should adjust prices on the material and object that was sold up. This number should be lower than the adjustment down, but it doesn't really matter how much lower, as long as it exists. Ideally, this is also a time for the shopkeeper to purchase items to refill the shop's inventory, and haul them to the shop.
As long as priority of shopping tasks is low enough, purchasers can continue to be affected by shopping tasks initiated by shops. There is a danger that distant shops will not be patronized, however. When a shopper visits a shop, the shopper should compare each item's current cost to a modified absolute cost. The modified absolute cost is made up of absolute value (ie, value you could sell to a foreign merchant) modified by individual preferences. I doubt that current preferences have scale, but they easily could. I suspect that preferences could lead to +25% (or minus!) to an item's value. With multiple detailed items, this could stack. If a shopper found that he valued an item at higher than its cost, he would attempt to purchase the item sold with the highest discrepancy-- if he had the money. If not, he would look at the item with the next highest discrepancy. He would attempt to buy all items that he valued higher than the shopkeeper, if he had the money. When he had no money to purchase any items that he valued more than the shopkeeper, he would quit shopping. He would then transport all items to one of his rooms. Ownership of multiple items should also reduce cost. Even if a dwarf likes earrings, he doesn't ALWAYS buy them in preference to amulets. Each item a dwarf owns should reduce his valuation of similar goods of the same type by a certain, cumulative amount-- say 10%. Second coffer is only 90% as valuable as the first, third only 81% as the first, etc.
Rentals would be treated as shopping tasks initiated from a noble (or a noble's room, if that is easier, or a new shop, if necessary). It would be treated like an item to be purchased. A dwarf would compare his current living situation discrepancy (perceived value minus actual cost) to each bedroom available. He would pick the largest discrepancy that he could afford. For EASY, I would suggest relinquishing ownership on previous rooms each time a room is bought (and so including current room value discrepancy in the list of rentals, to prevent see-sawing between the two best deals). A change in residence would generate hauling tasks that could only be answered by the moving dwarf (or, in the longer term, that would be PAID FOR by the moving dwarf). Although rentals would be automatically deducted each period, I would recommend not evicting a dwarf until his account was greater than negative the cost of the room. This would preserve some permanency even for this large periodic cost. That could be adjusted based on rate of shopping and rental tasks. The bedroom of an evicted dwarf should generate hauling tasks to his new room that can only be answered by the Sheriff (maybe, at least-- haulers might be okay). Items could be placed in barracks. A noble in charge of bedrooms, or a real estate agent, would periodically revisit real estate like shopkeepers revisit their shops, and change costs based on living space, component items like doors, and engraving status. As with shopkeepers, sold rooms should adjust prices of the same upward. As there are a variable number of factors, adjustments could be controlled by rooting to the power of the number of factors involved. A dwarf without floorspace should increase valuation of floorspace in rentals. This will encourage container purchases (see below) and automagically maintain appropriate bedroom sizes.
Easy! Now you have a self adjusting economy! In-demand items remain in-demand, but prices will eventually drop to accommodate all dwarves-- or raise to maintain subtle differences in standard of living.
HARD:
These aren't all necessarily hard, but they do all involve changes in gameplay, and have to be rebalanced against other factors.
New shops: Reduce military micromanagement, and improve consistency with Adventure mode. Weapon shops and armor shops. If your champion likes copper, well he'll wear copper. Tough titty. You will also end up with a more historically accurate military picture. Soldiers don't wear masterpieces-- rich people do.
Furniture shops: Seperate section because it requires more work. Reduce micro-ing of furniture. Dwarves replace beds, place coffers and cabinets. Pay no attention to dwarven preferences, because dwarves will pay attention for you. And hope you have some diversity, or prices on onyx will skyrocket. For now, bags should be exempt from ownership.
Credit: It's absurd that the bookkeeper ties you to coins. In reality, bookkeepers free you from coins. Abstract accounts (those not represented by concrete coins) should be incapable of purchase until a certain noble is attained. If the bookkeeper remains to start the economy, then it could be the hoardmaster, or the treasurer.
LONG-TERM:
Redesignation of shops as stockpile-type areas: Improve symmetry with adventure mode, and make more interesting fortresses. Designate a shop stockpile. Ideally, a shop would task a shopkeeper to collect a display (container or table), then to collect goods. And you get to make interestingly shaped merchant districts. Eventually, all stockpiles should be shops, with expenses compensated-- plant a plot, the govt will pay for your labor, and for the cost of the seed. Requiring upfront expenditure by laborers is dangerous, but interesting.
Other needs as purchased goods: Food is dangerous, but making it a purchased good should be doable (with a LOT of tuning). They can always hunt for vermin, right? Same goes for booze. This allows restaurants, grocery stores, bars.
Leisure as a function of income: Breaks should depend on income. If you have a bigger account, you will take a longer break. What do you need money for? Bridges nobles and peasants, and complicates income management. Ideally, breaks should cover all non-work needs: partying, shopping, etc. Dwarves on break should evaluate other jobs, but be likely to cancel them based on expected wage. Your ultra-rich legendary weaponsmith has hauling enabled? If you need a weapon, let him know; otherwise, party hard, my friend, party hard.
Hourly wage: Establish expected lengths of tasks (by observation, if needed) and establish payment per time spent, not per task. If a hauling task takes 1 day on average and pays 24*, instead pay hauling at 1* per hour.
Summer rooms: Why not allow multiple rooms? Apply a -10% worth modifier to a second room the same way you apply it to a second coffer, and maybe your richest dwarves want two bedrooms. So it shoves your haulers into the barracks? Tough, man. Learn a trade.
POTENTIAL PROBLEMS:
Coin bloat: The more important you make the economy, the more you exacerbate coin bloat. A credit noble, as suggested above, is insufficient to control coin bloat. Item restacking is important for other objects as well; it has to go in sometime. It will mostly cure coin bloat. The consideration of purses (or wallets, or pockets, or whatever) will help as well.
Legendaries and Nobles: They claim EVERYTHING. They take what they want. They never sell. That, umm, complicates economies.
Weird items: Eventually, shops should replace stockpiles. All items should be for sale. A mason should buy stones from the Miner shop. An architect should buy blocks from the Mason shop. But what about end-products? Who has any reason to buy a commissioned huge corkscrew that you never wanted to turn into a trap?
Happiness: The point of getting that onyx earring has always just been happiness-- but happiness is broken. When we have numbers like +1000 and +10 that exist side by side, it's clear that happiness is a careful balance that has not yet been attained.
Global economies: Foreign merchants are too easy to buy out. We use them to get rid of crap, not to get something that we want. That doesn't make any sense. If a good balance was achieved, seizing would occur strategically, not just for fun, and currency interchange would become meaningful.
Okay, I'm forgetting about a billion things, but that's long enough for now.