Crazy Population solution?

[Mowers]

One of things I was thinking today was that Vicky 1 was plagued by some bizarrely ahistorical population figures.

Now I don't know if there is a plan to tackle this but one of my thoughts was to have a population check routine that checks the current game population against what the world population was at the same time frame historically and if its within 20% then fine but if its much higher then have some sort of global famine event effecting all countries. That not only reduces the population growth rate but adds militancy to those folks without food.

Mowers

 

[Andrelvis]

If healthcare is more readily provided and there's a greater global agricultural productivity (due for earlier discovery of techs, for example), why shouldn't population be able to be higher?

What you mention would IMO be too deterministic.

 

[unmerged(203712)]

If healthcare is more readily provided and there's a greater global agricultural productivity (due for earlier discovery of techs, for example), why shouldn't population be able to be higher?

What you mention would IMO be too deterministic.

I don't think the agricultural technology at that time could support such rapid population growth.

Anyway, when an uncivilized AI controlled China had a rapid POP growth, the population growth mechanism in Vicky must be problematic. (Chinese population only grew by 10% in 100 year from 1840-1940)

 

[unmerged(138973)]

I think growth rates should be a little lower in VIC2. Several grand campaigns I played in VIC 1 had Germanys population at over a 100 million by 1900. This was usually within the historical borders. Historically Germany had about 64 million people in 1910.

 

[unmerged(203712)]

20%-30% higher than historical number is OK for me, but not higher than that.

 

[Andrelvis]

The population growth being slower is OK, but checking routinely to see if total population is within certain limits of historical population at that time seems a bit too deterministic to me.

 

[Zelvik]

There were some events in VIP that slowed down POP growth after a certain date. It was quite deterministic. But maybe there is a posibility to simulate a slow down of pop growth with the development of certain techs, or tie it to pop income. If pops are able to get their basic needs satisfied they procreate massivly. If they cant satisfy them or can satisfy higher level needs their growth rates will get smaller.

 

[Mowers]

If healthcare is more readily provided and there's a greater global agricultural productivity (due for earlier discovery of techs, for example), why shouldn't population be able to be higher?

What you mention would IMO be too deterministic.

Right, you could easily improve te model with a simple matrix in that checked the level of some key agricultural indicators.

 

[Aeon221]

There were some events in VIP that slowed down POP growth after a certain date. It was quite deterministic. But maybe there is a posibility to simulate a slow down of pop growth with the development of certain techs, or tie it to pop income. If pops are able to get their basic needs satisfied they procreate massivly. If they cant satisfy them or can satisfy higher level needs their growth rates will get smaller.

Or, here's a thought, if they start making more money, they consume more food.

That way keeping per capita income low causes the population to expand faster, since the consumption of food per person will be lower, while per capita income rising causes demographic expansion to level out -- and, incidentally, would cause the population to develop, over time, a higher average age than in poorer nations.

If you keep up with modern demography you'll note that this is fairly realistic -- modern France, for example, has a smaller economy than modern China, but a higher per capita income and food consumption per person as well as a higher average age. And you'll note that the poorest countries on per capita terms tend to also be those with the highest rates of population growth.

Now, I'll be the first to admit that these are not necessarily causative relationships -- it's entirely possible that a hornier than average populace results in higher population growth and therefore a lower per capita income. But many economists feel fairly confident that there is a loose inversely proportional relationship between per capita income and birthrate.

 

[dunka2]

I think the main issue, with China at least, is that the devastating wars and revolts that ripped through China are never simulated properly. The Taiping rebellion is a good example, as between 30 million and 100 million people died in that. No one is terribly sure as no one knew the population of China in the first place. Then there are the great floods of the Yellow river which killed millions and let loose devastating starvation across China. All in all, the different extenuating circumstances that affected China during this time aren't modeled, so the population you end up with near the end of the game is probably what China would have had if none of the disasters and revolts had happened. In a game I'm playing now, I currently add 6 million people a month, and since the beginning of the game I have added 200 million people. I now stand at 590 million and will most likely breach 1 billion by the end of the game once I get the right techs. That's a little off I should say .

 

[Baneslave]

Aeon221: IIRC, consciousness now modifiers consumer goods usage, so there is that if nothing else.

 

[DredMorte]

I think that if you have 100 years of unrivalled freedom, prosperity and peace, then you should have a very high population growth. Almost every country in the world has gone trough great turmoil during these 100 years, a good example being that of China, has written above. Others simply had (very) bad government policies.

The USA, with the exception of the Civil War and Slavery, had 100 years of peace and, to the best of my knowledge, unprecedented freedom. The growth of population was HUGE.

As a player, I have no intention to repeat the mistakes of the historical characters. I want to do everything perfect and therefore, outdo them in every way. I want to have, amongst other things, a population far bigger at the end of the game, than the one of real life, if I worked well enough towards that goal.

 

[unmerged(28057)]

The USA, with the exception of the Civil War and Slavery, had 100 years of peace and, to the best of my knowledge, unprecedented freedom. The growth of population was HUGE.

Wasn't that mostly through immigration though?

 

[Mowers]

I think that if you have 100 years of unrivalled freedom, prosperity and peace, then you should have a very high population growth. Almost every country in the world has gone trough great turmoil during these 100 years, a good example being that of China, has written above. Others simply had (very) bad government policies.

The USA, with the exception of the Civil War and Slavery, had 100 years of peace and, to the best of my knowledge, unprecedented freedom. The growth of population was HUGE.

As a player, I have no intention to repeat the mistakes of the historical characters. I want to do everything perfect and therefore, outdo them in every way. I want to have, amongst other things, a population far bigger at the end of the game, than the one of real life, if I worked well enough towards that goal.

Whilst I see your point, one can not entirely escape the socio-economic changes huge population growth would entail. Overly rapid urbanization in a country that does not have the almost unique dynamics of the Americas in the 19th century would lead to social tension simply because such a rapid social change could not be matched by an equally rapid change in political power unless there was severe upheveal.

 

[wilcoxchar]

They just need to take some of the factors that led to the demographic transition of the western world during the 19th century. Tying pop growth to literacy or income would be a good way to simulate this. Farmers obviously want a lot of kids to work on the farms with them, but as the population becomes more educated and urbanizes, the birth rate was lessened. However, you also have rapidly declining death rates with increased medical technology.

The problem is that the game needs to model both the second and third phases of the demographic transition model in quick succession in some countries, while others are still languishing in the first phase. While China only grew by 10% during the Vicky time period, the British Isles grew by 300%. I think tying certain pop growth rate modifiers to techs would be good for simulating declining death rates, while literacy and income would model the decline in birth rates. If we could tie it to issues that would be even better, but I'm not sure that's possible.

 

[OHgamer]

There were some events in VIP that slowed down POP growth after a certain date. It was quite deterministic. But maybe there is a posibility to simulate a slow down of pop growth with the development of certain techs, or tie it to pop income. If pops are able to get their basic needs satisfied they procreate massivly. If they cant satisfy them or can satisfy higher level needs their growth rates will get smaller.

But as POPs become wealthier and move up in the social scale, they have historically had less children on average than previous, poorer generations. This was seen in Western Europe as early as 1900 (and earlier in France) so that even before WWI there was a good deal of public debate over the slowing rate of population growth.

This is what VIP models with that event, it's not just something we came up with out of thin air, but ties to a nation's level of technological advancement, so that it only fired for advanced industrial nations.

 

[OHgamer]

Wasn't that mostly through immigration though?

not entirely, birthrates among Americans whose families arrived more than two generations earlier were, up to the early 20th C quite high, especially for the majority that remained in the agricultural sector (which was a majority in the US until IIRC the 1910 census), immigration simply added on even more to the population which would have gone up a massive amount otherwise.

 

[gamer42_au]

Historically (certainly up to the industrial revolution) population growth was limited to the rate of growth of food supply, which could increase only due to:
a) increased use of land
b) more intensive use of land (higher labour input)
c) better techniques (improved crops, better methods, etc)

Obviously, increasing labour input has declining marginal value and also increases the population directly dependent on the land, ie reduces the surplus available to support non-agricultural employment.

Europeans generally dealt with the constraint by starting families late (when the head of household acquired their own land), which resticted family size. Elsewhere infanticide or birth control was used to limit family sizes, or (more rarely) a cycle of over-population and famine.

Chinese population growth rates were low during the Vicky period in part because it already had extremely intensive agriculture (albeit by way of very high labour input) by 1840. Furthermore it has limited access to other sources of food (unlike the UK). Hence it had much less opportunity to expand its pop.

By comparison, the New World had very large (mostly untapped) resources (eg land) which were developed during the period and fed both the expanding American population and also that of Europe (esp the UK). The easy availability of land was the primary reason for the rapid expansion of the US population (both natural growth rate and immigration).

In terms of Vicky mechanics, there should be limits to the expansion of food RGOs (in particular all Chinese and most Indian RGOs would start fully expanded) and also there should be more severe consequences for pops which don't meet their food requirements. Hence most countries (except the high prestige ones that can adequately access any international food surpluses) would need to meet their own food supplies, tending to limit pop growth that allowed by increased farmer pop sizes plus gains from tech improvements.

 

[henryjai]

A gameplay mechanics I would like to see is.


1. Exponentially decaying function of POP growth rate with respect to population.

2. Exponentially increasing emigration rate with respect to population.


point 1 and 2 combined you should see a saturation point for the population, where emigration rate would balance the growth rate and resulting in no population growth in that city. I think this is the most elegant solution to this problem.

for 1, we could have medical techs/agricultural advances tied to it, that the function would drop slower for higher med. tech/higher life rating, and the saturation point would be raised.


When I mean exponentially decaying, I think it is something like this:


pop_growth_rate = A*exp[ -*Population^B/(life rating^C)]

where A is the pop growth rate determined by medical tech, B and C are constants,

a demonstration would be setting A to be 0.15, B to 1, C to 2, and Population be measured in thousands (k)


i. a 20k population, life rating 40 would grow at

pop_growth_rate = 0.15*exp[-20/40^2] = 0.148 #14%


ii. a 20k population, life rating 30 would grow at

pop_growth_rate = 0.15*exp[-20/30^2] = 0.146 #14%


iii.a 200k population, life rating 40 would grow at

pop_growth_rate = 0.15*exp[-200/40^2] = 0.132 #13%


iv.a 200k population, life rating 30 would grow at

pop_growth_rate = 0.15*exp[-200/30^2] = 0.120 #12%


v. a 2 million population (2000k), life rating 40 would grow at

pop_growth_rate = 0.15*exp[-2000/40^2] = 0.0429 #4%


vi. a 2 million population (2000k), life rating 30 would grow at

pop_growth_rate = 0.15*exp[-2000/30^2] = 0.0162 #1%


definitely not a very good model(the curve fall off too quick), but never the less it seemed to work. If we replace B with 0.75


i. a 20k population, life rating 40 would grow at

pop_growth_rate = 0.15*exp[-20^0.85/40^2] = 0.148 #~15%


ii. a 20k population, life rating 30 would grow at

pop_growth_rate = 0.15*exp[-20^0.85/30^2] = 0.147 #~15%


(better! a low life rating is less significant at low population)


iii.a 200k population, life rating 40 would grow at

pop_growth_rate = 0.15*exp[-200^0.85/40^2] = 0.141 #14%


iv.a 200k population, life rating 30 would grow at

pop_growth_rate = 0.15*exp[-200^0.85/30^2] = 0.135 #13%

(the life rating is beginning to show significance)


v. a 2 million population (2000k), life rating 40 would grow at

pop_growth_rate = 0.15*exp[-2000^0.85/40^2] = 0.100 #10%


vi. a 2 million population (2000k), life rating 30 would grow at

pop_growth_rate = 0.15*exp[-2000^0.85/30^2] = 0.073 #7%


(this is becoming clear that a low life rating would support much less population)


vii. a 20 million population, (20000k), life rating 40 would grow at

pop_growth_rate = 0.15*exp[-20000^0.85/40^2] = 0.008 #0.8%

(good, this is what we want, at least roughly)

vii. a 20 million population, (20000k), life rating 60 would grow at

pop_growth_rate = 0.15*exp[-20000^0.85/60^2] = 0.042 #4%

(New York would still be growing with 4.2 %, not bad)


I have plot 3 graphs using an online graph plotter for the above formula, A=0.15, B=0.85, C=2


life rating 30

life rating 40

life rating 60

Another constant setting is B=1 (That is more convenient, stupid term actually), and C=2.2

life rating 40

still, I am not quite satisfied with the shape of the curve.


If adding one more term of emigration, let's say emigration_rate = 0.00005*exp(A^0.1), we'd get

life rating 40 (saturation point around 16000k, a bit high IMO...but it should take very long to reach such a high number)

life rating 60 (saturation point around 40000k, well, fine, this model is very simple though, increasing C would shift up the saturation point.)

This is all the math I could muster, someone good at differential equation should help out.

 

[unmerged(63310)]

Because of world market and constant mechanics shared by all the POPs in the game the growth rate is deterministic no matter what. However it is initially set will be off at some point. Compared to V1 I would prefer to see slightly slower growth at the start of the game and technology and infrastructure increasing growth so by the end world population would probably end being higher than historical almost guaranteed but would vary more by country and the overall population wouldn't be surpassing historic levels until after 1900 at least.

I remember playing Italy and achieving 500 million Italians by 1900 with high plurality and force migrating POPs to highest life rating provinces. That is of course unrealistic in more than just the % growth rate we are talking about but the only reason I even bothered to attempt it was due to the high % growth rate making it worthwhile.

Trying to model realistic curves without actual input on what V2 uses to determine growth rates might be futile. Probably the easiest way is to use technology to speed up growth even though all historical data available points to a correlation between income and pop growth rates. Anything else is likely to lead towards backwards game play as people attempt to max their % growth rates.