Move the goods. Move the money. Let the consequences land.
That is the rule behind the market in The Long Century. Every game day, populations, resource operations, workshops, factories, state buildings, and governments put their needs and output into the same economy. Grain does not become an abstract prosperity number. Iron does not vanish once a factory has asked for it. A buyer needs money, a seller needs stock, and a transaction only happens when both are there.
The result is an economy you can follow from a field or mine to a household, a factory floor, a government stockpile, and back again.
Begin with what exists
Set each good's price from yesterday's result. The market records how much was offered, how much buyers wanted, and how much actually changed hands. Demand that outran supply pushes the next price upward. Excess supply pulls it down. Prices stay tied to each good's base cost, with a floor and ceiling, so they can signal a shortage or glut without becoming nonsense.
Then reset the day's ledgers and let every country act.
Mines, farms, and artisan workshops produce physical output. Factories turn their inputs into new goods. Pops put money aside for the things they need. Buildings file orders for maintenance and ingredients. Governments buy for their stockpiles. Each request names a good, carries a budget, and belongs to a real buyer. Each offer names the operation that produced it.
Start locally. Every country has its own submarket, where its producers and buyers meet first. A domestic farm can feed a domestic pop. A local factory can buy the material it needs before the remaining offers travel farther. Money goes from the buyer to the seller, goods enter the buyer's inventory, and the unsold remainder stays visible to the larger market.
This is not one anonymous national total. It is a stream of concrete requests and concrete offers, arriving from an entire country at once.
Join the larger pool
Merge the country submarkets in great-power rank order. Their remaining requests and offers become the world market's lists for each good.
The world market works with pools. For a given good, it gathers eligible supply into seller-country buckets inside a shared supply pool. That pool is rebuilt every day. It knows how much each country contributed, how much of that contribution has sold, and how much revenue belongs to it. The game can therefore treat available grain, coal, cloth, or tools as a common pool for matching purposes without losing track of the producer who must be paid.
Make production available that day. Goods that remain after local trade join the world market for the same day's settlement, where buyers can draw from the wider supply pool. Output enters, demand reaches for it, and the market carries the result forward into the next round of prices and production.
Serve buyers from the pool. Buyers spend only the money they allocated and actually hold. If the pool runs dry, later requests go unfilled. If a pop cannot afford grain, it does not receive a fictional meal because the interface would look tidier. If a factory cannot secure inputs, it has less with which to work. Scarcity becomes a constraint felt by the people and institutions living inside it.
Pay the sellers from the same pool. Revenue follows the goods that actually moved, rather than being assigned to a vague national balance. A mine, farm, workshop, factory, state building, or government that supplied the market receives the proceeds of its sale.
Let politics shape the route
Apply trade rules while the pool is being drawn down. Sphere members receive a priority round that can draw only from supply within their sphere. After that, the market opens to permitted trade. Embargoes block the exporting country from the embargoed buyer. Active wars block trade between belligerents. Export bans keep a country's relevant goods out of the pool altogether.
Charge the importing buyer its tariffed price. The seller still receives the world price for the goods sold, while the importing government receives the duty. This makes trade policy a real choice in the flow of money and goods, not a percentage floating in a menu.
Great-power rank matters here as well. Buyers are served in rank order, and sellers are settled in that order. In a tight market, priority is power with a human consequence: the country that reaches the pool first may keep its mills running while somebody else's workers face an empty inventory.
Watch the pools beneath the goods
Post labour demand before production begins. Every state also has a conversion pool: employers post the workers they seek, and the pool calculates wage pressure and occupation-conversion factors for the pops in that state. Mines, farms, workshops, state foci, state buildings, and factories all feed that demand side.
The goods pools and labour pools make the economy feel large because neither is sealed off. A profitable factory needs inputs, employees, and customers. A shortage makes its inputs dearer. A new operation adds output, asks for labour, and changes the prospects of the people nearby. A war can close a foreign source. A tariff can make importing less attractive. The numbers move, but the movement has a place on the map and a group of people who feel it.
Let the market tell the story
Build more farms to put more food into the flow. Open a mine to feed an industry that has been waiting for metal. Protect a sphere's access to vital supply. Raise a tariff to collect revenue and accept the higher cost at home. Each action enters the same daily chain of requests, pools, purchases, payments, and price changes.
That is why we do not resolve the market with a scripted outcome. A shortage is not a red icon added because the game decided a crisis would be dramatic. It is an empty pool, an unfilled request, a higher price tomorrow, and a decision that suddenly feels heavier because the world answered back.
Next diary: the people inside this system. We will look at how pops meet their needs, change occupation, and reshape a province over time. Until then, the forum is open.