Blog ‐ 2025 June Part 2
Now I have a cash based market system:
- price of goods is set by the market, initially by fiat, and adjustments are made based on supply and demand
- agents bid more food than wood than furniture in a 16/4/1 ratio
- agents have inventory limits, with a max of 2 furnitures per agent, otherwise 20 for other goods
- food and wood is consumed 1 per round, while furnitures have a 2% chance of break down
- the hungriest people get to buy goods first
- if supply > demand, each seller gets the same ratio of sold/ask
Biggest difference from the EconSim implementation in Unity is there is an agreed upon market price at the outset of each round. This removes market inefficiencies where goods are available to trade but the agent asks for too much and no one buys it, which drives more demand the next round and impacts pricing erratically.
There is also inheritance, when an agent dies (whether by starvation or age), their descendants get an equal split of the inheritance. If there are no descendants then the government gets it. The government will then redistribute the money as welfare to everyone who is currently hungry in equal portions. I plan on implementing servants or other means of spending government money soon, but that would require taxes first.
An aside on death by age, I'm using stats by age binned by decade. I believe the life expectancy is roughly 240 rounds. This was arbitrarily decided to smooth out the population trends (at 80 rounds there was a lot of oscillation in the professions and I didn't like that...)
Starvation has been generously extended to 20 rounds, and getting at least 1 unit of food will reset that hunger meter. This way the population can buffer against food shortages or temporary money issues. Next up on my to do list is banking and lending.
Price drops with time. The overall population also increases, so that mostly makes sense when the supply of cash is fixed at around 1000 for the system. Inventory over time is a little hard to make out, but on a per capita basis the number of furnitures per agent goes toward 2, the maximum, but so does wood? Food is much more erratic, although there is no inheritance of goods. So goods do fall through the system when an agent dies, and it is quite a bit (not pictured).
Cash vs time is an interesting one. Initially when max inventory was 20 for every good for each agent, carpenters would get all the money early on and they'd have nothing to spend it on as they would only buy 1 unit of each good each round, as would anyone else as long as they can afford it. Limiting furnitures to 2 per inventory slowed down money accumulation to carpenters, and forcing 16 food and 4 wood per round redistributed the money better. The sharp drops is likely when a rich person dies and their offspring are not of the same profession. As in round ~200 blue drops but green moves up by the same amount. The carpenters had some farmer offsprings! Now there is no life cycle of agents, the round they are born they start working until they die. It would be fun to add childhood and student hood that that just complicates things that I don't want to worry about right now.
Hopefully, when I add a bank that will push prices up along side population growth. crosses fingers