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One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Sat Apr 28, 2012 1:15 pm
by Argeus_the_Paladin
... Or "I tried to port Europa Universalis III to the Ren'Py engine and got a huge mess of code for my effort."

First off, my apologies to Greeny and any other I have contacted at around this time last year for a doomed project - if they are still around, of course. Suffice to say real life and other issues set in and my plans had to be scratched entirely because of that. My apologies for keeping you guys hanging - if I did at all. Let's hope this one does not end in such an epic failure as my last one.

Anyway, let me explain myself in greater detail.

1) What is One Province Minor (OPM)?

In Europa Universalis, an OPM is a nation comprised of only one province. That's it. Very easy to manage in theory, yet in practice puny and ultimately easy prey to the bigger players out there. Hence in EU, it takes nothing less than a skilled player to handle an OPM well.

Now here is my idea: The player is given control over an OPM and given a time span of fifty year - fifty to a hundred "turns" so to speak. During that time, he has to turn this puny, feeble nation into an economic, military and/or political powerhouse or die trying.

Unlike any other strategy game, however, the player does not order people around to do things directly. Instead, he is given a range of "decisions", "policies" and "reforms" to undertake, each will change the various factors underlying the nation's behavior based on socio-economic rules - most importantly supply and demand - so as to coordinate and shape it to his liking.

For instance - and right from what I have done - the nation's population growth is influenced by a combination of market food price, political stability and employment. Market food price, in turn, is affected by natural demand and supply of food, which is in turn affected by number of people working in agricultural sector, which is in turn affected by agricultural tax rate and available arable land. In that entire chain of factors the player can only change the tax rate and maybe, maybe try to keep his nation's stability up high.

In other words, I seek to push the engine to the limit so that it doesn't stop at telling a story, but become a political-economic simulator in and of itself.

2) What's the catch?

The catch? I may be somewhat experienced in writing and economic-political theories, but I am no coder, and I certainly am no artist. Hence, this thread is less like an advertisement for my WIP and more like a help/announcement thread. If, at some point, I manage to come up with a halfway competent simulator, I'd holler around for artists and musicians. If.

3) Current progress?

a) Economic simulation:
- Agriculture: 50%
- Industries: 0%
- Service, Trade and Export/Import: 0%
- Working Inflation Model: 0% - and I am seriously considering to scrap this idea. Inflation can seriously mess up the maths for little real gain.

b) Political simulation:
- Political stability and its impact: 10%
- Factionalism, radicalism and reform resistance: 0%
- Defeat and victory conditions: 0%

c) Military simulation: 0%

d) Technology simulation: 0%

e) GUI, artwork and music: Negative infinity percent. Not a typo.

Yes, it's pretty much in its start.

4) How can I help?

Ideas. That's what I need the most now. I need ideas for random events first and foremost. I have at present only four recurring events with a varying chance of happening every turn - food shortage, food surplus, food hoarding and prosperous times - based on such indirect factors as agricultural labor utilization, food price, government policies and technological breakthroughs.

Hints and suggestions. That's the second biggest priority. I'll try asking in the technical forum as well, but if at all possible I'd ask here.

The third and fourth most important things, dedication and time, I guess I have to come up with myself, don't I?

In other words, thoughts, comments and suggestions are very, very much welcomed.

The introduction and character creation demo can be found here.

Re: One Province Minor (Economic Simulator)

Posted: Sun May 06, 2012 10:47 pm
by Argeus_the_Paladin
A progress update:

While I'm still struggling with the basic economic model and the coding for that, I've gotten somewhat of a broadstroke framework for the story. In a nutshell, you will pick one of five playable characters. All five characters have, at the time the story begins, deceased. Their ghosts will "possess" the ailing Kurfurst of Ulmster and essentially make his decisions for him.

These are the characters I have planned thus far:

- Leopold I of Anhalt-Dessau, a Prussian general in the early 18th century. Owing to his experiences in running a country and a military, he's essentially "beginner mode". Based on the real life Leopold von Anhalt-Dessau.
- Edward Gibbons, an English historian. Thanks to his extensive historical writing, he's got some armchair experience in stately matters. Based on the real life Edward Gibbon.
- Armagan Nezin, a Turkish writer-diplomat. An expert in diplomatic matters and a patron of the arts, but not much use elsewhere. Based on the real life Aziz Nezin (satirist) and Armagan Yavuz (creator of Mount&Blade).
- Arthur Andersen, a modern Danish accountant and financial expert. The authority in national economic, administrative and monetary issues, but is generally subpar in all other respects. Based on the real life Arthur Andersen company (responsible for the Enron corporate collapse last decade.)
- Sekai Izumi, a borderline hikikomori Japanese schoolgirl having died in a rather weird accident, with literally zero experience in how to run a nation. When she hear 'inflation' she thinks of a balloon. When she hears 'military drill' she thinks of Tengen Toppa Gurren Lagann. And so on and so forth. Based on... well, I doubt I need to tell who she's based on, right?

As far as mechanics go, my progress in setting up the agricultural system has been as such:

- The Kingdom of Ulmster, a one-province minor in the Holy Empire, has a population of 100000 people at the year of 1650, in which roughly 40% are in the labor force. 5% of the population are the nobility, who controls 80% of total agricultural land and hold 60% of the population as their serfs. 10% of the population are free farmers with their own land to cultivate, and the remaining 10% are craftsmen, merchants, guildsmen and urban folks.
- In exchange for the nobility's land and protection, serfs work their farm and submit any and all agricultural surplus to their feudal overlords. The nobles have free rein to sell these products however they see fit, but are obliged to pay a sum of tax based on their total manorial income to the crown. This tax is levied in ducats.
- On the other hand, the free farmers are entitled to the sweat of their own brows, but they have to pay a sum of tax based on their land to the crown. This tax is levied in grain and goes straight into royal storehouses.
- Town craftsmen buy food, cash crops and other materials from either manorial estates or from import, turn them into industrial goods and sell them however they see fit. However, they have to pay a tax based on their total trade value. This tax is also levied in ducats.
- The crown also has an option to form its own crown-owned enterprises as a means to control quantity of food and industrial goods circulated in the market. In this case, the crown pays for all expenses and takes all profits from such enterprises' operations.

I am having trouble creating a general price level model, since (i) the market was decidedly not free, and (ii) the fact that you can import food from a (generally) perfectly competitive global market means that food shortage is not going to be a huge problem. Meaning that relying on a supply-and-demand model won't really work out.

Thoughts and suggestions are very welcome.

Re: One Province Minor (Economic Simulator)

Posted: Thu May 17, 2012 10:56 am
by Andrei
Hello. After playing the major names in strategy from Paradox, creating a socio-econo-political simulator started grasping my imagination. It's several months since I've started thinking hard, and although I've done little in a concrete way (such as making lists of factors), a general plan exists in my mind. One of my major preoccupations regarding this plan is trade. I'll start by criticising a little EU's commercial simulator:

First off, the produce of a province doesn't necessarily go to a centre of trade. It can be traded via several routes, and in determining these routes market forces have a great influence. If one were to believe EU accurately describes reality, then the only incentives binding several provinces in trade would be their cultural, religious and political affinities, which is false. Venice and the Fatimid Caliphate had radically different culture and religion, but this didn't prevent a flourishing trade relation to exist between them. In EU there isn't even a shadow of long-range trade. For instance, in the Middle Ages, cities like Trebizond or Tanais had huge benefits from the fact that they were the Western ends of transcontinental routes stretching all the way from the Far East.

I think that each unit of produce from a province should have it's own trade route. And I think that the factors determining the forming of a route should be divided in conditions and incentives. Conditions are absolutely necessary for a trade route to form, incentives only encourage or discourage the forming. Conditions are as follow:

1. The political relation between the two countries must be above a certain value.
2. The existence of commercial infrastructure (docks, warehouses etc.)
3. The existence of transport methods (merchant fleets, mules, carts etc.)
4. The commercial taxes must be lower than a certain value.
5. The existence of a product that is supplied by a market and demanded by another one, in a ratio that is profitable for the merchant.

Incentives are as follow:

1. A political relation value higher than the minimal one.
2. A taxing policy more advantageous for the merchant than the maximal one.
3. A large gap between supply and demand, in favor of demand.
4. The existence of resupply posts owned by the merchant's government, or owned by a government friendly toward the merchant's government.
5. Cultural and religious affinities.
6. Naval technology and other types of technology that lower death-rate at sea, make transport easier and so on.
7. Political stability.

More thoughts will follow. I'm just starting my intellectual engines.

L.E. Please clarify the make-up of the population in your stated Kingdom of Ulmster. And what social classes will there be available in the game.

Re: One Province Minor (Economic Simulator)

Posted: Thu May 17, 2012 12:31 pm
by Argeus_the_Paladin
Very interesting thoughts. Thank you.

The progress of the economic module is currently as such:

- The entire (very primitive) system I have got at the moment revolves around the three agricultural classes: Nobles, serfs and free peasants. The first own lands but does not work, the second works but doesn't own land, the third works their own land.
- From their farm composition, these classes will turn out three types of agricultural products: grain, cattle and cash crops. The first two are edible, and all three are harvested based on a land's acreage of the particular product (I found out that the average acreage at the time period was 8-15 bushels per year, depending on your sources).
- The consumption pattern is as such:
+ Farmers will eat grains and sell all the surplus in the national market.
+ Serfs will eat grains and pay a certain rent to the nobility, which is all their surplus or 20% of their production, whichever is greater.
+ Nobles eat everything and sell all of their surpluses. Granted per capita they consume much more than the other two classes.

Farmers and nobles will pay a sales tax to the crown based on the amount they do sell on the market.

Here is where I hit a stump: I want to simulate a market effect of food - as in, demand and supply forces deciding a general price level. However, for a few reasons this system does not work out so well. First off - a market-based economy hasn't existed yet back then. Second, if all the three classes above produce food, there will naturally be no one to buy food until I factor in the town burghers, patricians and plebeians, which will snowball the code out of my control. And third, you don't derive a base price level based on a baseline demand and supply markup, but rather a demand and supply function. So what I will have to do is to derive a rather arbitrary supply and demand linear curve, have them intersect, figure out the equilibrium price and shoot away. In essence, this doesn't work, since for the most part back then farmers and nobles tried to produce as much as they humanly could.

I am still looking for a way to simplify the model, but if this goes on my only option is to go "screw it" and to exert a static price level. Which is neither interesting nor accurate.

By the way, I'm quite curious about how you found this thread, since for a long while it seems to have gone nowhere. Did you come from the Taleworlds or Paradox Plaza forum, or have I seen you somewhere before? (Granted, I had never really been part of the latter, but just throwing it there).

Re: One Province Minor (Economic Simulator)

Posted: Fri May 18, 2012 3:55 am
by Argeus_the_Paladin
Right, I have compiled the "character-creation" and introduction of this game into a demo file. To give a rough indication of the scale of this project, the introduction and character creation alone takes up a whopping 9000 words. As far as I know, there *probably* shouldn't be any bugs aside from the occasional typos.

Unfortunately, as I have confessed, I am no artist and definitely no musician. Hence, at the moment it reads like the first chapter of a novel rather than a game proper. This is also a pleas for help: If anyone feel like they could lend a hand, please by all means inform me!

This demo file can be found here.

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Fri May 18, 2012 6:59 am
by Andrei
Yesterday I had searched "europa universalis" supply demand on Google, and the 9th result was your thread. Regarding art, I can do some drawings, given the fact that it's almost 5 years since I've started studying architecture. Let me comment on your economic model:

-I've nothing major to say on the serf-FP-nobleman system. It sounds very reasonable. As a bonus though, slaves should be thought of. They, as the serfs do, work the land without owning it, but they have fewer rights than the serfs. Before the New World, Europe already traded in slaves. The Pontic Steppe was one of the regions from which they were "harvested", and they were sold in Black Sea ports, the Venetians and Genoese regularly acting as middlemen in bringing them to Europe. After the Black Death, when England lost half it's labor force, the earlier-mentioned republics made a huge profit from Caspian slaves.
-I think there should be another division of agricultural products. What are the elementary needs of peasants? (Think of the Anno series) - food, alcohol and clothing. Meat wasn't financially accessible to them, only fish. So I reckon the four main products needed are bread, fish, a cheap drink (wine perhaps) and cheap garments (made of flax, hemp, maybe wool or cotton, certainly not silk). So, I think that the main agricultural products should be: grain, fiber crops, livestock and cash crops (although livestock is also a cash crop). I think that livestock itself should be divided in: bovine, porcine, ovine and equine. Bovine give meat, leather and cheese. Porcine give meat and leather. Ovine give meat, cheese and wool. Equine give war steeds, which was an important resource back then. Equine can also stimulate trade by procuring mules. Countries that have vast and leveled spans of land will have a great bonus in breeding horses, whilst for a country like Switzerland that would be almost impossible on an industrial level. You should also consider that a village placed on a river or on a seashore will only give fish/seafood. You should also consider that a diversity of food types in a market will assure a balanced diet, thus boosting population growth.
-I have nothing to say on the consumption pattern. It sounds OK.

I'll meditate on the market price generator. What you say pretty much makes sense. It's wise though to sketch out the social composition of a country before thinking of how the market works.

L.E. By acreage you mean average yield per acre?

L.E.2 I'm adding the following four commercial incentives:
8. Lack of pirates, brigands etc.
9. Administrative efficiency of customs and other agencies that control the flow of goods (prevents unending cargo lines etc.)
10. Shortness of distance.
11. Experience of merchants.

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Sun May 20, 2012 8:01 am
by Argeus_the_Paladin
These are fair inputs, but I am not sure if we can implement all that just yet. Right now, just to get a little on the technical side, each instance in the "population group" class (which is to say, social classes) already have a few dozen variables to their name, and that is before the agricultural model is even finished. Adding or making things more complicated at this stage will only jumble up the code and increase the likelihood that something will break.

My brainstorm yesterday results in an alternate pricing model for food item: Maybe a demand and supply model based on equilibrium price won't be established (since, as a prototype, I'm only modelling out the social classes that actually produce food), but one where price is affected by the percentage of demand satisfied can work out, at least as a placeholder until we come up with something better. Say if total food demand for a year is 1 million bushels, but farms, fields and fishing can only produce the equivalent of 0.8 million. This will increase the price of food by a factor of 1/0.8.

Furthermore, there is a 'baseline' food demand that the populace simply HAS to have, as in the bare minimum required to survive and reproduce labor, say, about 70% of base demand. If production drops below this value, the population will "dig" into their savings to buy food to raise their consumption to this level, at whatever the cost. That will require the modelling of a "saving" system, where the theoretical money each social class produces on a yearly basis will be aggregated and carried over to the next year in a "saving" variable, with a certain percentage of decay to represent miscellaneous expenditure - frivolous or otherwise. In the case of emergency spending as mentioned above, this "saving" figure can drop below zero to represent the fact that a sizable portion of the population is in debt, which will lead to all kinds of fun unless the government - you - do something about it.

The problem here is at this point I'm still running round in circles in regard to how I should model the range of products that a social class has got to sell. Programming-wise, it's still very foggy at the moment. I can try to add more variables into the model (and indeed the engine should allow for an arbitrarily large number of variables), but that also has the effect of making the codes that much harder to parse and that much more likely that something is broken.

YOur inputs are very much welcome.

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Sun May 20, 2012 12:36 pm
by Zylinder
So I played the intro, and I must say I really like it. The tutorial was really well-made, with personality choices and their effects properly explained. I take it that that's the standard for western-strategy RPGs usually, but it's still a very nice touch. Even without the pictures, the description was good enough that I could actually see in my what the judgement room would look like/the ambient. There were one or two typos that I found but forgot to write down, but it's not life changing or anything. Plenty of time to beta as it goes.

Really looking forward to this one, so good luck with it!

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Mon May 21, 2012 10:59 am
by Andrei
Argeus_the_Paladin wrote: The problem here is at this point I'm still running round in circles in regard to how I should model the range of products that a social class has got to sell.
Explain please.

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Mon May 21, 2012 5:51 pm
by Argeus_the_Paladin
@ Zylinder: Thanks. I hope you enjoyed reading the introduction as much as I did writing it (Because that I certainly did) :D

@ Andrei:

It is mainly a technical issue with Python. I find it rather difficult to put into words, but I'll try.

The backbone of the programming at this point is based on a "Population" Python class, with each population group being an instance of this class and is defined by a number of variables - name, number of people, number of people of labor age as well as agricultural production, consumption and the likes. Ideally when the entire economic model is complete these variables should cover any and every property of a population group.

However, I am running into a brick wall as to how to model the number and type of products that a given population group puts up for sale in the national market. My first idea was to create a "list" of products each class has for sale as a reference point, but then I was unable to link that list with the products produced variables. The second idea is that I can, for each product a given population group produces, I will create additional "foo.sold" variables to represent how much of said product is sold and link it with the products produced by another formula or two. Thing is, given that there are going to be a lot more products than just grain, cash crops and cattle, this will undoubtedly lengthen the class definition into something within the neighborhood of a hundred variables or several. And as I mentioned before, less variables = better at this stage.

Of course, there is the fact that I am much, much more of a writer than a programmer. I'm pretty sure there are ways to optimize these codes that I haven't found out.

Apologies if I haven't been very clear with this description.

@ Anyone else who might have chanced upon this thread:

I've put this here for like one month now and there is only some 400 views and one reply from the common forum community? Don't be intimidated by Andrei's and my walls-o-text - speak your mind! :wink:

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Mon May 21, 2012 6:01 pm
by Samu-kun
It sounds like a pretty interesting project. I would say making such a project would appeal to statisticians, so I hope you have a strong background in statistics!

A problem is that there are already a large number of similar and more complete products in the market right now, like Europa Universalis, so it'd be important to distinguish your product by doing something different.

I'm not sure how much of this board's audience would be interested in an nation simulator, but I'm down for playing it once the nation building aspects are implemented. So good luck!

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Mon May 21, 2012 6:26 pm
by Argeus_the_Paladin
Samu-kun wrote:It sounds like a pretty interesting project. I would say making such a project would appeal to statisticians, so I hope you have a strong background in statistics!
It's more like a historical and economic demanding than statistics, IMO. The latter deals with the analysis of data to reach a conclusion, the former are about simulating and creating a working and accurate model that correctly reflects the way things used to be back then.

I realize my knowledge of both is still insufficient. Economic-wise, I kinda sorta took only one very basic course at uni, and history-wise I was quite uncertain about how the Imperial Prince-Electors worked (and how incredibly inefficient a system it had been, but that's neither here nor there) until a few weeks ago when I started researching for this project. Which is why any idea I could get in regards to these topics are very welcomed.
A problem is that there are already a large number of similar and more complete products in the market right now, like Europa Universalis, so it'd be important to distinguish your product by doing something different.
I mentioned EU from the very first post. :wink:

In all honesty, yes, you're right. Paradox Interactive is the undisputed king of this genre, and I was by no means trying to compete. I am a Paradoxian / Taleworlder at heart, and all I want to do is to honor my favorite publisher, genre and modders with this admittedly crude imitation of their masterpieces, and also because I personally believe the Ren'Py engine can be used to do so much more than dating sims and romance visual novels.
I'm not sure how much of this board's audience would be interested in an nation simulator, but I'm down for playing it once the nation building aspects are implemented. So good luck!
Thanks! Will do my best!

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Tue May 22, 2012 10:19 am
by Andrei
Samu-kun wrote: [...]there are already a large number of similar and more complete products in the market right now, like Europa Universalis[...]
I think that despite all favorable appearances that this game has, it's pretty incomplete, simplistic and shallow, and gameplay becomes awfully monotonous and tiresome after a certain point. The wall of numerous options and panels stuns you at first, and there's a lot to learn, but afterwards you get that sour nothing-new-under-the-sun taste. Why, for instance, can't I change the goods of a province? Why are provinces limited to a single goods? Why doesn't province area affect it's economic performance? Why are colonies limited to 1 unit of production? Why can't I change the taxing policy of my country? Why can't I assassinate rulers or generals? Where is the clergy and the nobility trying to override my authority? Why can't I have a single glimpse of the social composition of my country? These are important issues that EU doesn't satisfy, and there are a lot more.

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Wed May 23, 2012 1:05 pm
by Argeus_the_Paladin
I've been struggling throughout the day trying to find a good way to map out the variables in an easy-to-read way. This is proving to be far more complicated than I thought at first. Which is why I'd request some brainstorm in these direction:

1) What the model currently is:

For the sake of programming, I am thinking about putting all products (which means the very basic products I've spoken about earlier - the three kinds of agricultural products together with consumer, luxury and industrial goods) into a class. PyTom's given some incredibly helpful comment, but at the moment I could not interpret his code very well, which means for the sake of the basic model I have to push through with brute-force programming. :(

Now, the disadvantages of putting all products into a single class is that it will be rather difficult to model out the properties specific to each kind of goods and the social classes that produce them, such as agricultural goods are produced based on land, industrial goods based on the level of industrialization and raw material, and so on. I have to resort to lump all these factors into a single "modifier" variable at the moment.

An overview of the model I have got so far is as such:

- Every product has a base price and a base demand per capita (the other part of the equation, base supply, is tied into a social class' production capacity) that remains for the most part unchanged.
- For every product each population group also has a "consumption threshold", as mentioned above, which is the minimum level of that product they demand in order to keep on existing. Or keep on being posh/fashionable, but the point remains.
- Actual price will be determined by three things: Base demand, base supply and elasticity (as in, how much would price increase-decrease be proportionate to increase-decrease in demand and supply? Not the textbook definition, but it's close).
- Every social class, for every given product, will consume first out of what it produces before trying to buy more at the market. In other word, if supply > demand, they'd consume all of their demand and sell the surplus. If consumption threshold < supply < demand, they'd consume all of their supply. And if supply < consumption threshold, they'd consume all of their supply and buy the difference between their supply and their consumption threshold at the market.
- Every social class' income from selling their surplus and expenses from satisfying the consumption threshold will be aggregated.

2) Direction for development:

- Export/import. Where should exporting and importing fit into this model? Another issue to be considered is my favorite food-for-thought lately: "Who pays for export/import?" Also another issue to take into consideration is even though we're speaking of a small country, in times of shortage import is not always going to be timely to feed into the market. How should we go about emulating that?
- The nature of each social class and how it should play into the model. The above model makes the incorrect assumption that each social class act in a perfect market where they can buy and sell at will. It also takes no heed of the fact that "unfree" lower classes don't actually get to own much of their resources, which are seized by their landlords as rent. What can we do to emulate this?
- Unit of measurement. What should the basic unit for measuring each product be?
+ For grain, it's most definitely bushel.
+ For cattle, should it be "heads of cattle" or "kilogram/pound of meat"?
- In the same vein, what should the base demand of basic agricultural products be? The base demand for grain for an average Joe back then was something along the lines of 12-15 bushels per year, but what about other categories of food? Basic consumer goods? Luxury goods for the wealthy?

Andrei, I'm counting on you :D. Anyone else who would like to lend us a hand, feel free to jump in! Your opinions will be much appreciated :wink:

Re: One Province Minor (Economic Simulator) (Intro Uploaded)

Posted: Fri May 25, 2012 2:07 pm
by Andrei
I think that there should be a variable in the game called Commercial Tradition. The higher the CT of a nation, the higher another variable called Merchant Speculation, which practically is the merchant class' ability to predict gaps between supply and demand and reduce them. So, the higher the CT, the higher the chance your merchants will have, at the right time, at the right moment, the right thing to sell. The mind of man is limited though, and one cannot predict for instance crop failures. Which happens then is that the prices of grain will soar, population growth will stagnate temporarily, until your merchants bring grain from abroad, thus lowering the price of grain, but still keeping it higher than normal. What do you mean by who pays for import and export? Those who demand it and afford it. If nobles demand perfumery, and the internal market can't supply, your merchants will go fetch it from abroad, given they will turn a profit. It takes time before they react; the higher the CT, the shorter the time. So the first who pays is the merchant, because he must acquire perfumery before selling it. He can take loans from bankers, which are an important institution for commercial stimulation. The state can also pay subventions or give benefits in order to stimulate trade, such as offering trade ships to merchants or lowering income taxes.
Argeus_the_Paladin wrote: - The nature of each social class and how it should play into the model. The above model makes the incorrect assumption that each social class act in a perfect market where they can buy and sell at will. It also takes no heed of the fact that "unfree" lower classes don't actually get to own much of their resources, which are seized by their landlords as rent. What can we do to emulate this?
This pertains to the political aspect of the game. There should be laws and decisions for pushing your economical policy towards feudalism, state capitalism or liberal capitalism.

I think the measurement unit should necessarily be universal. The reason for this is that the player will have a hard time comparing the prices of different goods if the prices also vary according to unit. And the most obvious unit is the metric tonne.

Demand for food per individual should be based on calorie consumption. Average modern day is 2500/day for adult males, 1900/day for adult females. 1.1 kg of bread assure the daily caloric need for an adult male. If he also has fish, 500g of bread and 350g of cooked fish will be enough (to which we also count 50g or so of oil/butter/animal fat, because, as I said, it is cooked). Cattle meat is much costlier, because salt is also needed, in order to deliver the meat from putrefaction. Needless to say, salt is pretty expensive. Fish doesn't need salt, because you take from the ocean a quantity very close to what you need. When you kill a cow, you get a much larger quantity of meat than needed. If one eats 500g of bread per day, he consumes approx. 11 bushels of grain per annum. I reckon this is a pretty large quantity, but it was even larger in reality, because cereal-based foods and drinks provided ~90% of calorie intake for peasants in the Middle Ages. I'm still confused about the right answer. I'll keep on reading. I think this could be useful to us: ... eene-paper