Population Model v. 0.1

[heardie]

Population
Created: May 23rd 2000
Updated: -

There is a popular demand for a better population system. This is a description of a system that intends to satisfy that demand. I will be updating this when things are discussed and decided. From the beginning of the description you can see, when it was updated, and what was changed.

The key idea is to use "population units". Each tile could have several PU's. All the individuals in the PU belong to the same "group". Each group has these things in common:

-ethnicity (this means to what tribe they originally belonged to)
-religion (regardless of how the religions are handled)
-location (in same tile)
-owner (the civ that "owns" them; this can be also none)
-controller (the city that controls them; this can be also none)

In every tile there is only one PU belonging to the same group. So, the amount of individuals is not any fixed number, but rather the actual amount of people.

Every PU has also some properties specific to it:

-amount: the total amount of individuals
-reproduction: the net amount of new individuals produced per turn (the net amount means the amount of new-born members reaching adult age, excluding the members dying naturally)
-happiness: this is the average value describing how content the people are to their living conditions
-age structure/workforce %: either a simple percentage of people in the working group, or the amount of children, women, men, and seniors.
-professions: the amount of people exercisig each profession
-workhours: the amount of hours spent working per year
-creative energy: a figure showing the "free time activity" of the PU
-efficiency: the percentage of workhours used for actual work

If the PU hasn't got a controlling city, they are independent, but still produce stuff to the region they belong to. IF it hasn't got an owner civ, they work only to get living for themselves. This is mainly for primitive tribes.

When a city or tile is conquered, the PU's in it preserve their ethnical identity. At certain point, some citizens may "change" their identity (when new generations start to born) and their original ethnical group loses members to the conquerer group. Some kind of "immigration" between ethnicities. This is affected by how the host population treats the conqured one, among other things.

In certain situations it might be possible that two populations merge forming an entirely new ethnicity. This could happen for example when the two populations have same rights, and the other pop isn't very much smaller. This would be especially likely, if the populations belong to a region that declares independency from some other nation - like in America. It will take some time (dozens of turns) for the new ethnicity to create its unique culture.

I hope I can update this soon. -amjayee


Are you sill using this?

[amjayee]

Umm... Basically, but as you can see in the beginning of the thread, we have moved a bit further from that early idea.

[The Joker]

I just realized that my age group submodel will require a bit more work. I am hoping to post it tomorrow. It is really not that complex, it just needs some last minute adjustments.

------------------
"It is only when we have lost everything
that we are free to do anything."
- Fight Club

[S. Kroeze]

Dear Amjayee and Joker,

Thank you both for your kind words! And I agree with almost all conclusions you arrived at in the meantime.

Since I don't have much time I have not succeeded in finding a good general study on agriculture and production yields so far. Some reliable information you might find useful can be found at www.britannica.com in the article on 'history of agriculture'. Ofcourse this is probably more detailed information than you need; unfortunately the article does not contain concrete numbers.

A problem with production yields is that in general the technological progress occurred very slowly and gradually, almost imperceptible until the nineteenth century. There were only two major breakthroughs: the Agricultural Revolution starting after 10,000BC and the Industrial Revolution. To give you an idea of the developments during the intermediate period I give a short citation:

'The principal consequence of Russia's location is an exceeding short farming season. In the taiga, around Nowgorod and St Petersburg, it lasts a mere four months in the year (from mid-May to mid-September). In the central regions, near Moskwa, it stretches to five and a half months (mid-April to the end of September). In the steppe, it lasts six months. The remainder of the Russian year is altogether unsuitable for agricultural work, because the soil is hard as rock and the land is covered by a deep blanket of snow.

In western Europe, by contrast, the growing season lasts eight to nine months. In other words, the western farmer has at his disposal anywhere from 50 to 100 per cent more time for field work than the Russian. Furthermore, in parts of Europe where the winter is mild, the winter months can be employed for occupations other than field work. The economic and social consequences of this simple climatic fact will be elucidated below.

The brief growing season, and its corollary, a long and hard winter, create an additional difficulty for the Russian peasant. He must confine his livestock indoors two months longer than the western farmer. His cattle thus misses out on the early spring grazing, and when finally set free in the meadow it is in a thoroughly emaciated condition. Russian livestock has always been of an inferior quality, notwithstanding attempts by the government and enlightened landlords to improve it; imported western breads have promptly degenerated to the point where they became indistinguishable from the miserable domestic variety. The difficulties in raising livestock have discouraged efficient meat and dairy farming in the forest zone. They have affected adversely the quality of the draught animals and caused perennial shortages of manure, especially in the north, where it is most needed.

The consequences of Russia's poor soil, unreliable rainfall and brief growing season have been low yields.

Agricultural yields are most meaningfully measured in terms which indicate how many times the seed reproduces itself: when, for example, one grain cast at sowing time gives five grains at harvest, we speak of a yield ratio 1:5. The typical yield ratio in medieval Europe was 1:3 or at best 1:4, the minimum yields which make agriculture worth while and create conditions capable of sustaining life. A 1:3 ratio, it must be noted, means an annual doubling rather than tripling of the sown seed, because each year one of every three grains harvested must be set aside for seed. It also means that one acre of arable out of every three has to be devoted to seed production. In the second half of the thirteenth century, west European yields began to experience a significant rise. The principal cause of this phenomenon was the growth of cities, whose trading and manufacturing population had given up growing food, buying it from farmers instead. The emergence of a rich urban market for cereals and other products encouraged western landlords and peasants to raise a surplus by more intensive use of labour and heavier manuring. In the late Middle Ages, western yields rose to 1:5, and then, in the course of the sixteenth and seventeenth century, they improved further to 1:6 and 1:7. By the middle of the nineteenth century, countries with advanced farming, headed by England, regularly obtained yields of 1:10. Such a dramatic improvement had an even greater economic significance than might appear at first glance. Where the soil can be depended upon regularly to return ten grains for each grain sown, the farmer needs to set aside for seed only a tenth of the land and a tenth of the harvest, instead of a third of each, as he must do under a 1:3 yield. The net return on a 1:10 yield is 4,5 times what it is under a 1:3 yield, making it theoretically possible to sustain in a given area that many more inhabitants. The cumulative efeect of such a surplus over a number of years can be readily appreciated. It may be said that civilization begins only where one grain of seed multiplies itself at least five times; it is this minimum surplus which determines (assuming no food imports) whether a significant proportion of the population can be released from the necessity of raising food to pursue other occupations. 'In a country with rather low yield ratios highly developed industry, commerce and transport are impossible'. And so, one may add, is highly developed political life.

Like the rest of Europe, Russia averaged in the Middle Ages ratios of 1:3, but unlike the west, it did not experience any improvements in yield ratios during the centuries that folowed. In the nineteenth century, Russian yields remained substantially the same as they had been in the fifteenth, declining in bad years to 1:2, going up in good ones to 1:4 and even 1:5, but averaging over the centuries 1:3 (slightly below this figure in the north and slightly above it in the south). Such a ratio generally sufficed to support life.

The trouble with Russian agriculture was not that it could not feed its cultivators but that it never could produce a significant surplus. The productivity lag of Russia behind western Europe widened with each century. By the end of the nineteenth century, when good German farms obtained in excess of one ton of cereals from an acre of land, Russian farms could barely manage to reach six hundres pounds. In Russia of the late nineteenth century, an acre of land under wheat yielded only a seventh of the English crop, and less than a half of the French, Prussian or Austrian. Russian agricultural productivity, whether calculated in grain yields or yields per acre, was by then the lowest in Europe.

The low productivity of the Russian soil, however, cannot be blamed entirely on the climate. Scndinavia, despite its northern location, attained already by the eighteenth century yield ratios of 1:6, while the Baltic provinces of the Russian Empire, where the land was in the hands of German barons, in the first half of the nineteenth century had yields from 1:4.3 to 1:5.1, that is, of a kind which made it possible to begin accumulating a surplus.'
(source: R.Pipes: 'Russia under the Old Regime',1974)

I hope this information to be of some benefit. Is it?

I might add that in tropical or subtropical regions it was often possible to harvest two or even three times a year. This declares partly the success of Egypt and Sumer. Even with low crop yields such a region can produce a lot more food than regions in the north or south. I hope that the influence of climate will be increased. Without irrigation Sumer was infertile, part desert, part marshlands. With irrigation technique it became the cradle of Civilization! CivII underestimates this phenomenon by only adding one food to irrigated desert. Depending on the fertility of the soil, irrigated desert will often produce more than rainshowered grassland, which by the way is quite uncommon without human interference. Once Europe consisted mainly of dark forests and marshes!

I agree with your ideas about regions and their relation to cities. Yet I think that every region under political control will have some centre, however small. When you allow towns of 1,000 inhabitants without substantial growth, you can reproduce those political structures.

I am not happy with the introduction of ethnicity. It cannot be denied that it does play its role in human affairs but it shouldn't be exaggerated. American blacks, though sometimes discriminated, are in general loyal American citizens. The Serbs and Croats are ethnically identical. They hate each other because of differences in language and religion. There are many other examples I could give (Swedes/Danes, Flemings/Walloons etc).

So I propose to replace ethnicity by language. Often a conquered population will asimilate the conquering nation. Ethnically the population is mixed, but one of the languages gives way to the other. And languages change with time: different dialects will develop into different languages, whose users will not understand one another any more after some centuries.
The most spectacular example is the story of the Indo-Europeans. Around 4000BC a language was spoken somewhere in southern Russia. Gradually the population spread, migrating in all directions and conquering many nations. From this single language many tremendously differing languages developed: Hittite and Lydian, Armenian, Sanskrit and Hindi, Avestan and Persian, Greek, Latin and Spanish, Gaulish and Irish, Gothic and English, Old Church Slavic and Russian, Lithuanian, Tocharian, Illyrian and Albanian. As you probably notice this list is far from exhaustive.

Sincere regards!

[amjayee]

Hi again, S.Kroeze, and thanks for your informative message! These kinds of messages are surely useful, as they give us new ideas and better vision of what we are to model in the game. You are welcomed to send as many of them as you can!

I think our system will model most of the aspects presented in the game. The amount of surplus food should definitely play a large role in the development of a society.

I'd like to add in your message, that the success of Egypt and Mesopotamia were greatly based on the rich soil of the river valleys. But irrigation should not be underestimated. Plus; desert tiles can be fertile, they are deserts just because there is no rain. Proper irrigation might turn a desert tile into a paradise. Fertility of the tiles will be taken into account in the map model, and it has nothing to do with whether the tile is desert or not; this is decided by rainfall and temperature, etc.

About ethnicity; the ethnicity of those afro-americans is American, if they are loyal to that ethnicity. If not, they would preserve their original ethnicity. New ethnicites are created during the game; in our game, ethnicity does is not excactly how we understand it in our world. It is more like what ethnical, national and language group the people feel they belong. So, there might be Serb and Croat ethnicites, even though in our world they have the same ethnical background.

Each civilization will have an ethnicity; if new civilizations are born, they get their own ethnicities. So, the ethnicity of a group of people tells us, to what civilization they feel they belong - whether that civilization exists (is independent - conquered civilizations continue to exist as regions of the conquering civ) or not. So, we would have both ethnicity and_language. Hope this clears things out.

[The Joker]

My connection was really poor, so I clicked Submit Now several times without anything happening.

#1
[This message has been edited by The Joker (edited August 24, 2000).]

[The Joker]

#2
[This message has been edited by The Joker (edited August 24, 2000).]

[The Joker]

#3
[This message has been edited by The Joker (edited August 24, 2000).]

[The Joker]

Hey guys!

For some reason I couldn't log on to Apolyton monday night, and since I was out of time the next two days I could not post my age group submodel untill today.

But here goes:

Following is my age group submodel. It will only handle the population on a single hex, although all the hexes in a region (except for the cities) would have the same characteristics (mortality and birth rate). This, however, is not entirely realistic, as a nice grassland hex would propably have a lower mortality than a jungle hex. But to avoid using endless amounts of calculations and RAM on this, not too important matter, we should just use the region and city system.

The age group submodel uses a simple age system, in which the population is divided into some age groups. This means that it will be recorded how many people are in each group. Combined this is the population of the region. These would either be 10 year groups or 5 year groups, depending on how many ressources we want to use on this system. For me the 10 year groups would be fine. There would be two age group lists – for men and for women.

The birth rate is determined via a formula. First the age where people start having kids is determined (A), mainly via a formula using education levels and tech levels. Then the age where people stop having more kids is determined (B). This will propably just be a percentage of the life span (the life span will be determined via the health level of the people). B-A=C – the total amount of years people have kids. Via the age groups the amount of people in the reproductive ages is calculated. So if the age people start having kids is 20, and the age where they stop is 35, and there are 500 people in the 20-30 group and 400 people in the 30-40 group, then the total amount of people in the reproductive ages would be 500+400/2=700. In the game it would propably work so that the amount of women in the reproductive ages is calculated and the amount of men in the reproductive ages is calculated, and then the lowest of these numbers (a war could kill a lot of the men, for instance) would be used as the number of families with kids in the province (D). Then the number of kids per family (E) is calculated, using mainly cultural things, education levels, women’s tendencies to work and the length of the reproductive ages. It is assumed that the kids are spread evenly over the reproductive ages, so the following formula could be used to determine the amount of newborns in the province: E*D/C. This amount will be added to the 0-10 group.

Then a series of simple calculations are made through all the age groups starting with the first. First the amount of new people (people entering the age group) are added. For the 0-10 group this will be the amount of newborns. Then the mortality rate for the particular age group (it would be determined by the overall health levels, and then put into a formular which would make the mortality rate different for each age group) kills off a percentage of the people in the group. And last 10% of the survivors are substracted by the group, as they will be moving up to the next age group. For the next age group these 10% from the previous group will be added, then the mortality rate kills off a percentage of them and then 10% of the survivors will move to the next group. This is done throughout the age groups. One age group will have a mortality rate of 100%. This will simply mean that all the people that enters it will die instantly.

Ok, this is pretty much my age group submodel. It is not really very complex, but it adds a lot of flexibility, as the mortality rate changes throughout the game, which will mean that people will live longer, have kids longer and work longer.

I think that the different classes should propably have different mortality rates, as the wealthy have better access to medical assistance. At the same time the different groups (nationalism and religion) will have different birth rates, due to cultural differences. It is needed to determine how many kids are born of each group, and how many people die of each class, but it shouldn’t really create any problems.


Hi again, S.Kroeze:

quote: ...I give a short citation.

I love your posts!


Anyway, I agree with Amjayee. It was a really informative post. Food supply is truly important for the growth and prosperity of a civ. When we have come a bit further in the development of our game we will need some numbers on how many people one farmer can feed in different climates and different tech levels. This is really essential for the realism of the game. I think you might very well be the best person avaliable to find such information, if you would like to help us with it! Right now, though, we just need to work out a way to have people in our game.

About ethnicity and language:
I think Amjayee covered this pretty well. Ethnicity is simply a combination of language, culture and the nationality that people feel loyal to. Besides the actual nationality of a group I also think that all nationalities should have a certain variable in relation to each other, meaning how close 2 ethnicities are. This number would have effect in diplomacy, migration and much more! It would also provide a way to let far away provinces develop their own ethnicity - slowly their "variable" towards the home ethnicity rises, and when it reaches a certain point, the province would get a new culture - the point where the province gets a new culture wouldn't really matter gamewise - only the value of the varible would - but it would mark the point where a colony had a new culture with a name.

------------------
"It is only when we have lost everything
that we are free to do anything."
- Fight Club

[amjayee]

Thanks Joker, your model sounds reasonable. I think we would have quite realistic chances of making it. Also I think we should keep track of most population statistics for each class separately. I will give this some thought and pull everything together in the next pop model version!

Ethnicity and language: I agree completely. Also I think we need the figure telling the relationship between the ethnicities. It would be very useful in many circumstances. About new cultures being born, I'd like to add that it could be possible that new "ethnicities" in game terms could be born even before the region becomes independent; usually every region would have their oen ethncity almost instantly, but it would be so close to the home civ's ethnicity, and it would have so few members, that it would not be very significant. I think this would depend heavily on the distance to the home civ; neighboring region on the same continent would feel much closer to their home civ than a region on different continent on the other side of globe.

[Guildmaster]

I'm not quite sure what string to post this in but I think this one will do...

Are we going to have a "numbers catalog?" Say for example we could do all calculations simply by assigning every variable an alphanumeric code...
eg.
demand for steel=a101a1
demand for coal=a101a2
or something like that, and then if we like we can have all the indexes listed in a separate .txt file where the player can tweak just about anything as far as naming goes. The point I'm looking for, is why not do functions with these numbers instead of recalculating each variable for each function?
Not that I know anything about programming...

Also I was wondering does anyone know how to change your signature? I want to change mine from "Goober" to "Peace and trust can win the day despite all your losing - Led Zepplin"

[The Joker]

I really think Apolyton should get a faster connection. It is rather annoying to double post all the time.
[This message has been edited by The Joker (edited August 26, 2000).]

[The Joker]

I agree, Amjayee. In fact I think that no two provinces should ever have the exact same ethnicity. Maybe the relationship between the ethnicity of two cultures should be portrayed by a simple number between 0 and 100. if the number is 0 then the two provinces have the exact same culture, if it is 100 then they are as different as can be. Maybe when the number between your capital province and another one hits 10 the other province's ethnicity gets a name. Mostly the the central provinces in your empire will have values of less than 2. But often far away provinces would have values upwards of, and sometimes higher than 10.

The development of the value for a province compared to your capital one would depend on distance, trade between the two and migration between them. But other variables (like the climate of the provinces) could also have some, smaller effect.

But I also think that the chance of a colony revolting would depend on more than just it's ethnicity. If you have a really high tax rate for a province and don't use much of the money earned in it on the people in the province the chance of them revolting would be higher than otherwise.

------------------
"It is only when we have lost everything
that we are free to do anything."
- Fight Club

[amjayee]

Guildmaster: I'm not excactly sure what you are meaning.

Joker: Yes, the connection is really slow. At some time, I kept double posting a lot. Then I learned, that you need to click only once, no matter how long it takes the confirmation message to appear. It appears, that the message is transferred instantly, but updating the thread takes a while, and that causes the waiting time. Once my connection to internet was dropped almost instantly after I had hit the submit button; after the connection was re-established, I sent the message again, and made a double post. From this I learned, that I can hit the button, then hit back button two times to get back to the thread list... but I agree that apolyton could be faster.

I agree with the ethnicity thing. Also I'd like to note, that even if the region has its own ethnicity, in the beginning the majority of its inhabitants will belong to the original ethnicity. And of course ethnicity should be only one factor determining the revolting of a region or other things.
[This message has been edited by amjayee (edited August 27, 2000).]

[Guildmaster]

About connections peed:
I as wondering, what kind of connection are you guys using over there across the ocean? I know that when I log on to apolyton from home it's not any slower than any other site, so I wouldn't notice what you guys are talking about. But the library here is using ethernet (I think) or DSL or something like that and so is the university so then I notice that apolyton is so slow I can go start it loading and have time to get something to eat before it's done loading. The thing is, the cable company doesn't offer ethernet in my apartments yet... and the phone company doesn't offer a high-speed connection yet either so all I have is a regular 56k phone modem which connects at the usual 28.8. Seems archaic, and to hear you guys talk I fell like I'm living in the dark ages over here. So I was wondering what it was like over there?

Anyway about ethnicity...
Maybe this might be a little unnecessarily complex, but would it be any benefit to have ethnicity & sub-ethnicity? Take for example:
Ok I am an American, I am also from California. Or perhaps, someone from France might be Dijonaise or something. Ok that's a little rediculous

Anyway this is my two cents: Infastructure and communication should play a MAJOR role in determining the development of newer ethnicities and the evolvement of old ones. eg. The United States as it is today is roughly the same geographic size as Rome at the height of power. Rome split up partly as a result of differing cultures and lack of adequate communication between them. Moreso due to other reasons, but it played a role. Perhaps if the different ethnicities didn't exist, the split up might not have been so fragmented.

This could easily be a factor in the transportation/communication supply and demand relationship. Supposing those demands are not met the cultural differences index would go up one level at a time until a certain area developed a unique language and culture. If the demands are met, the same index would go down to indicate the fusion of multiple cultures. This all is, of course, a degree relative to the actual percentage of the demand that is actually supplied.
I would say that for communication, the default demand index would indicate everyone wants little watch-sized communicators like they have in Star Trek and the ability to hold holographic conversations with friends across the globe on a whim. Naturally this won't be available when they're still cartrying mail around on a donkey so a certain percentage of the default demand would not be met, and therefore modify the culture index accordingly.
Then say that if 70% of this demand is met, there is no change in the index. Anything above would lower it.

For transportation demand, the default value would represent everyone wanting the ability to teleport from point A to point B instantaneously using little teleport belts and stuff (maybe?) Each technology when it becomes applied raises the supply depending on exactly how much of a given technology is available (#of cars per capity vs. $ spent on public transit per capita)

Anyway I will write more later bye