Population grow formula makes no sense

[FearSunn]

Suddenly I've realised population grow is total nonsense in this game. Increasing population makes it harder to get new pop. It should be in the contrary: more population - easier grow. It is exponential in real world. More people - more babies - faster pop grow. Of course objective limiting factors should be taken into consideration like food, housing, happiness. But generally population natural grow rate should increase with each new citizen.

Now it is breaking the game for me (suddenly...). Please help me get my game back!

 

[Arent11]

Master of Magic had a slightly more realistic model in which both present population and limiting factors were taken into account.

In civ 1 it was assumed the most important factor is available food. Still that doesn't explain why subsequent population would need more food. It's a game mechanic.

 

[Melliores]

While the model is not completely realistic, it makes sense that a city/civ will have minimal food reserves, which depending on the population will be higher. Call it a first world issue - government policy + rising food prices (which have risen quite substantially in the last 50 years, as the world's population almost doubled) makes food inflation a thing.

In the real world it is not exponential, the contributing factor for the population jump in the last century was actually vaccines, antibiotics and better sanitation. Back in the day (read till the middle of 20th century) people would go for big families with 5 to 10 children due to the mortality rate among infants. A lot of them will not live to see their 5th birthday. As this is yet to be simulated in a CIV game, for a good reason, they kind of add it as an extra food requirement.

More people, more births, more deaths.

 

[FearSunn]

In the game each citizen already consumes food. He would die from starvation without food. Bigger population requires more food. This is ok. This makes sense.
The question realy is "Why subsequent population would need more food?" as @Arent11 already noted in his reply.

 

[bbbt]

It doesn't represent actual population, it represents a 'level' of population. Civ 5 had this explicitly with it's demographics screen. A user apparently calculated what each level represents with the demographics calculation in 5: https://forums.civfanatics.com/thre...a-city-from-size-1-to-40-to-test-this.416892/

And it is indeed not linear. So think of it more like a category 1 city, category 2 city, etc

 

[FearSunn]

It doesn't represent actual population, it represents a 'level' of population. Civ 5 had this explicitly with it's demographics screen. A user apparently calculated what each level represents with the demographics calculation in 5: https://forums.civfanatics.com/thre...a-city-from-size-1-to-40-to-test-this.416892/

And it is indeed not linear. So think of it more like a category 1 city, category 2 city, etc

In that case each population unit should be more productive than the previous one. But this is not the case. It is in fact quite the opposite. And even worsens my initial "problem".

 

[Mr Jon of Cheam]

What do you propose as an alternative? The whole game is based around working tiles, the population number is irrelevant beyond this!

 

[DJ_Tanner]

In that case each population unit should be more productive than the previous one. But this is not the case. It is in fact quite the opposite. And even worsens my initial "problem".

You are looking at the equation all wrong. You are treating everything a purely variable(i.e. each person requires x resources) and that would not be the case. In something like population growth you are going to have large outlays of resources at particular intervals that will not allow a purely linear growth.

For instance, a single family farm will have no issues feeding and growing as long as it remains within a reasonable number so 4, 10, maybe even 30 people could live and grow on just a single farm without much trouble and at those levels it would be a simple variable growth model. Each member requires x amount of food and produces y amount of productivity. Now lets grow that farm to 100, 300, or 1,000 people. Now we have new issues. At this level we can no longer have people pick something whenever they are hungry we need a central depository which requires people to run that depository, people to track the resources, etc. So not only do we have the variable portion that was the same when the population was small, we are adding in these large outlays of resources at set intervals to meet the demand for all of the support services that come with the demands of larger populations and potential new variable strains on those same resources that simply didn't exist when the population was smaller.

So the level model (while surely not totally accurate) may be a pretty good representation of population growth.

0 - 1,000: = x(pop) + 0
1,000 - 6,000 = x(pop) + a
6,000 - 21,000 = x(pop) + a + b + c(pop)
etc.

 

[TomKQT]

I think the current system works well for the game. Exponential growth would be crazy and a lot of other features in the game would have to be dramatically changed to work with it.
And it's not true even in real life that the more people you have, the faster the community will grow. They will get limited by housing, water, food, medical care etc (a lot of this actually IS in the game).

 

[FearSunn]

So, population unit represent more than one pop. It increases with each new pop. I am fine with this.
Now explain me why productivity is not increasing with each iteration? If 1 pop represents 1000 citizens and 2 pop represents 6000 productivity should be scaled accordingly.

 

[Arent11]

What do you propose as an alternative? The whole game is based around working tiles, the population number is irrelevant beyond this!

In master of magic/(master of orion) it went something like this:

(1) When a city was founded it was first a cottage & had to grow for several turns to become a city
(2) Growth was completely independent on available food & based on population (more pop = more growth) and surroundings/max pop. You basically had a growth curve - slow in the beginning, fast in the middle, slow as it approached the maximum possible pop.
(3) Food was only important to prevent starvation & to support units. The cheapest units in fact only used food & did not cost money. Which made food production very important to maintain cheap low cost armies.

 

[acluewithout]

So, population unit represent more than one pop. It increases with each new pop. I am fine with this.
Now explain me why productivity is not increasing with each iteration? If 1 pop represents 1000 citizens and 2 pop represents 6000 productivity should be scaled accordingly.

It sort of is.

What matters is less how many hammers you can produce, it is how many hammers you can concentrate in one place. So, while each Pop just lets you work one tile, so each Pop seems equally as good, the point is you’re able to work more tiles in one city.

Put another way, 50 hammers in one city is way more powerful than 5 hammers in 10 cities.

So, each additional Pop in a city is ultimately more valuable than the last, more or less.

This does go a bit wonky though when you consider yields that aren’t concentrated in one city. But it goes even more wonky when you consider bigger cities can sometimes grow faster because they can work more food tiles.

Basically. Pop and growth is a fairly rough and ready system. Don’t think about it too much.

 

[MrRadar]

Now it is breaking the game for me (suddenly...). Please help me get my game back!

Back in the time, when they still indicated the number of inhabitants in the city (as far back as Civ 3), you could see that pops were not being created equal. Every next pop unit represented a more numerous batch of new inhabitants, the number of citizens per pop grew... exponentially? (did it really? oh, well, let's say it did).
And the reasoning can be pretty much what @DJ_Tanner wrote above.
So... immersion restored?

 

[thecraftybee]

So, population unit represent more than one pop. It increases with each new pop. I am fine with this.
Now explain me why productivity is not increasing with each iteration? If 1 pop represents 1000 citizens and 2 pop represents 6000 productivity should be scaled accordingly.

If the 1st pop represents 1,000 people and the 10th pop equals 1,000,000, then the city is becoming more productive in terms of food as each level of population only requires 2 food.

 

[FearSunn]

If the 1st pop represents 1,000 people and the 10th pop equals 1,000,000, then the city is becoming more productive in terms of food as each level of population only requires 2 food.

Yes and no. You still need more food to get to pass the required treshold for new population unit. Then miracioulsly this new pop unit consumes the same amount of food as the previuos one. And then again production. It does not scale. True what @acluewithout noted that you get more concentrated production in one single city and this has some effect. But this concentration effect is going down with each new pop. This still leaves me uncomfortable.

 

[Dirichlet]

The whole pop being not linear in actual population is probably not helpful for this discussion. Population was always a make-belief number to have somewhat realistic population sizes both in Ancient and Modern Eras, starting from Civ 1. For gameplay purposes population is linear.

But Population might be a good factor to focus on for future Civilization games. One major missing link is between population and army size as well as the relationship between food productivity and number of people being able to being anything but a farmer. I think it might be a good idea to have something like this:

• Population increases relatively quickly (maybe ~30 turns?) to a theoretical maximum based on health, infrastructure and happiness
• Free Population depends on how much food surplus you can produce
• Production (hammers), science, commerce, production of luxury and strategic resources as well as culture is produced only be assigning free population to it
• Your military (soldiers) is also coming out of the free population pool. If you lose too many it takes some time for your people to replenish

This is pretty close to the Master of Orion 1 slider system, which was pretty good, except that tile improvement would still matter.

 

[Arent11]

Back in the time, when they still indicated the number of inhabitants in the city (as far back as Civ 3), you could see that pops were not being created equal. Every next pop unit represented a more numerous batch of new inhabitants, the number of citizens per pop grew... exponentially? (did it really? oh, well, let's say it did).
And the reasoning can be pretty much what @DJ_Tanner wrote above.
So... immersion restored?

That is actually true, but I never liked it. It is counterintuitive:

Compare this with master of magic, where each pop is 1000 people:

 

[Trav'ling Canuck]

This issue has been with Civ since the beginning.

The core issue for me is that excess food leads to faster population growth, rather than available food simply being a limit on growth.

Housing is at least an attempt in Civ 6 to start to work out a better system. Though I dislike "housing" as the term for what is actually a bunch of factors.

I think you could have a system based on:

Base Growth = Existing Pop
x modifier based on available food
x modifier based on crowding/disease
+/- immigration from the countryside / emigration to healthier nearby areas

Initially, all you could control would be food, so you'd want as much as possible spread over as many small cities as possible. Later on, technology would reduce the loss from crowding/disease and larger cities would start to grow faster. Immigration / Emigration should let newly opened up territory grow faster, as the population migrates on its own ("go west, young man!").​

 

[FearSunn]

The core issue for me is that excess food leads to faster population growth, rather than available food simply being a limit on growth.

For my tastes Food and Growth should be decoupled completely. Of course lack of food should lead to starvation and population decrease, but thats all. Population growth mainly based on food stockpile is just too much wonky for me.

 

[criZp]

I think the population growth thresholds are designed to keep the rate of population growth steady as a city grows more populous. With more population you can work more farms, giving more food surplus. The growth threshold increases to counter this and keep the growth rate steady.