Have they got population growth wrong?

[Boris Gudenuf]

Population Growth in cities is almost never directly related to 'available food' and has no relationship at all to 'excess food' as the game would have it now.
In fact, as I remember from a few Population Geography classes 'way back when (when I was at University the Vietnam War was Current Events) - and talking to my sister and her husband, who both have Doctorates in Geography - historically cities were lousy places to have and raise children, because before Sanitation/Germ Theory, a crowded city had a distressingly high mortality rate for infants and toddlers.
Therefore, up until the Industrial Era, most of the city population growth does not come from Food/birth rate in the city, but from people moving into the city from the countryside (or other cities).
Reasons for moving to a city were:
Protection - city walls lead to Population Growth
Access to 'Amenities' - as in, markets with varieties of food, craft goods from specialists,Culture in the form of Entertainment, etc
Access to Jobs/Making a Living - since cities concentrated the workshops and markets and warehouses and other structures that required labor
Access to Power and Culture - the Palace/Capital was always a market for Luxury goods, so artisans moved close to it, and if you wanted to Rise In The World, you needed to be close to the Throne - Capitals do grow faster, all other factors being equal.

So, we could have a much more synergistic model for Population Growth, based on All the resources available to the City, Bonus as well as 'Amenity', to create Jobs, and on construction in the city, since Districts and their Buildings also provide employment of all kinds. Extra Food and Housing does not bring people into a city, unless they can also make a living there. Libraries, Universities, Markets, Banks, Harbors, Temples and such do make people move to the city, looking for work and good pay. Lack of food and housing will keep people away from a city (or make them leave) which in turn may strangle the output of Districts and Buildings in the city for lack of workers.

Then, with the Industrial Era, 'modern' Sanitation/Health Care causes the Effective Birth Rate to skyrocket - not because more children are born, but because more of them live to be adults than before. In addition, mass work forces required by Factories attract workers seeking Jobs from Outside the City, and steam/internal combustion-powered transportation makes it much easier for the population to move from country to city and city to city. At this point also, the 'Food Producing Radius' of the city changes to Infinite, since food can be trucked, railroaded or steam shipped in from all over the world rather than carted in from the nearby countryside.

So, the early City Growth Dynamic should be based on Jobs, Protection and Amenities available to the city, while Housing and Food are only Negative Factors - excess does not count, lack will stifle growth. Then in the Industrial Era, just over the nominal 'half-way point' in the game, the factors in the Growth Dynamic change dramatically as food basically drops out of the equation completely and Jobs and Amenities - including, emphatically, Culture, Education, and Health Care in the city - become the primary factors in city growth.

People have been posting about the problems of Late Game Boredom: City Growth with a more 'realistic' - dynamic - mechanism, could require you to dramatically revise your city management in the last half of the game...

 

[playshogi]

Population growth is one area of the game that works well. The ideas presented so far suggests playing the Paradox game Victoria.

 

[Disgustipated]

I thought this thread would be about epidemics and Black Plague and what not. You know, the fun stuff.

Would be cool if your population took a hit and then after say replaceable parts tech, really take off. Replaceable parts tech is good, but sometimes I think it should be a little better.

 

[acluewithout]

@Victoria Excellent post. And excellent questions. So glad you’re back on these boards.

The current pop system works well, and is pleasantly uncomplicated, but it certainly has room for improvement. I am also bothered about the issues Victoria has pointed out about how pop growth works.

I’ve thought about pop before, and while there are lots of good things Civ could do, my thought is there are three constraints. First, not losing Civs game board feel, which rules out certain types of mechanics (eg no sliders). Second, overall complexity, given the current system has some depth without actually requiring too much micro. And third, knock on effects, given population impacts a lot of other mechanics if only weakly. These three factors make tweaking pop hard, but not impossible.

A few random thoughts:

- Civ’s philosophy seems to be linear population growth at the start and then a big jump after the industrial era. But because that “jump” is controlled by the player - they have to build neighbourhoods and sewers - the jump never really happens. You don’t reach a point where your population “booms” and your struggling to manage it.

- Put another way, you shouldn’t be building neighbourhoods and sewers to encourage growth; you should have to build Neighbourhoods etc to cope with your (rapid uncontrollable) growth.

- That would fundamentally require pop to grow based on some factor other than food or housing, and for food and housing to then be reactive to pop growth the way amenities are. Maybe your pop grows based on existing pop and technology, and then having sufficient food and housing becomes provides an amenity bonus and or yield bonuses (again like amenities do). Or maybe housing becomes largely unconstrained after the Industrial era, and Neighbourhoods and Sewers instead produce amenities or help you better utilise your booming population.

- Cities do sort of share food via getting food from internal trade routes. One thing I’ve started doing is running trade routes out of one or two cities or my cap to outer satellite cities, netting production and growth, and then when the route resets (and I now have a trading post), using the same route but instead going past that internal city to an international neighbour. You miss out on international yields at the start (which are better), but trade feels more organic and there’s less micro.

- Anyway. If cities aren’t going to share food, there should be a little more population movement. You capital should get people from less developed cities. That would make food heavy cities more useful, because they would actually grow your empire. Likewise, if you capture cities, some pop from the captured city should move to your opponents cities (which would help shore up their loyalty). I think there’s a mod that does that already.

- I don’t know how. And I think this is what Victoria”s post is gettting at. But Population growth should be something you struggle against and have to manage, rather than struggling to actually grow your Pop. Otherwise, there’s never any risk to you - there’s never a risk your citizens will starve or rebel.

Here’s a thought experiement. We know some people get really fast victories, and part of that strategy is having lots of cities with low pop to enable you to place more districts or chop resources. But what if that strategy was actually more high risk? Say populations could really boom beyond your control. Then, by the time you’re chopping in your spaceport and projects etc., suddenly the pop in all your “ghost” cities is just booming - which you haven’t been managing - and these cities start rebelling and destroying your infrastructure?

I don’t mean population growth should nerf fast victories. I’m saying: wouldnt that be fun? Sure, you can lean into fast development, but it all becomes high risk high reward.

 

[Magma_Dragoon]

I would like a civ game where food supply is global, pop growth exponential, with housing, food, amenities and diplomacy being limiting factors on growth. With a few modifications, this game's amenity system could reasonably abstract supply and demand economics, which would nicely compliment such a system.

Population Growth in cities is almost never directly related to 'available food' and has no relationship at all to 'excess food' as the game would have it now.
In fact, as I remember from a few Population Geography classes 'way back when (when I was at University the Vietnam War was Current Events) - and talking to my sister and her husband, who both have Doctorates in Geography - historically cities were lousy places to have and raise children, because before Sanitation/Germ Theory, a crowded city had a distressingly high mortality rate for infants and toddlers.
Therefore, up until the Industrial Era, most of the city population growth does not come from Food/birth rate in the city, but from people moving into the city from the countryside (or other cities).

True for Europe during medieval and renaissance eras, but was that true of classical era cities?

 

[Boris Gudenuf]

True for Europe during medieval and renaissance eras, but was that true of classical era cities?

Can't speak for Asian pre-Medieval cities, because I just don't have the data to hand, but, for instance, the Greek City States had a large class of people in the cities composed of those who lived in the city but were not born there, and in Athens they were between 50 and 75% of the total population, so the majority of the adults in the city had moved in, not been born there. Rome, which was a major Imperial Capital, notoriously attracted people from all over the Mediterranean, and the point has been made by many historians that the Roman Genius was that those people were still Roman Citizens with all the advantages and inclusion that gave, whereas in the Greek Polis the non-native were Never citizens, could not vote or hold office and had no political stake in the city/state.

 

[Trav'ling Canuck]

- Put another way, you shouldn’t be building neighbourhoods and sewers to encourage growth; you should have to build Neighbourhoods etc to cope with your (rapid uncontrollable) growth.

There's the gameplay hook, there. Make population growth a function of current population (a la the original board game rather than the food-based system of computer Civ) multiplied by a mortality factor (which could be based on a whole bunch of relevant factors that modify over time based on the map, where you are on the tech tree, policies, etc.). Then you get benefits from a larger population (higher yields, fodder for your armies) but you also need to deal with their expectations (unhappiness/revolutions if pop grows beyond available food/housing/sources of happiness). If you have a multi-cultural empire (i.e. one built by conquest) you get some additional happiness factors to manage on top of the normal pop growth ones.

 

[Forster]

Civ IV had cottages that increased in value but didn't actually reflect pops, I think. Civ VI has neighborhoods in late game which do actually allow for pop increase. I would think having the cottage mechanism leading to neighborhoods(suburbs) in later game would add interesting facet to Civ VI. Allow the cottage to allow 1 additional pop, village 2 and neighborhood 3 or more, as well as generate gold.

 

[PeterChu]

More 'realistic' pop growth will not get permission from a developer proud of the concept of 'digital board game'. You need to change the production mechanism as well, to say the least. In addition, though it would be interesting to see how some buildings could be related to the pop numbers (meaning: you can only build some specific buildings if the city have pop beyond certain threshold), it seem very unlikely for this to happen in the Civ 6. Same for the immigration mechanism.

Form cottages to neighborhoods is fun, and should not be hard to implement in the CIV 6 framework.

 

[Sostratus]

Civ’s philosophy seems to be linear population growth at the start and then a big jump after the industrial era. But because that “jump” is controlled by the player - they have to build neighbourhoods and sewers - the jump never really happens. You don’t reach a point where your population “booms” and your struggling to manage it.

My first reaction to this thread was this exact mechanic. Right now, getting near your housing caps essentially shuts off growth. There is a designed housing crunch that's supposed to happen late medieval-Renaissance that's alleviated by Neighborhoods.
The surplus housing effect on growth is currently set thusly:
2 or more: 100% (normal growth)
1: 50% (half growth)
0 to -4: 25% (quarter growth)
-5 or less: 0% (no growth).

Now we can see why they did this: if housing is to mean anything at all, it has to curb growth at some point. I think the mistake was having the growth curb come in right before you reached the cap. What a lot of people seem to want is that feeling like your cities are becoming overcrowded - the huddled masses yearning to breathe free, if you will, especially once you get the replaceable parts farm boost. As you've surmised, we don't get big cities unless they have housing- meaning we need neighborhoods. So there's never going to be overcrowding because it would take the entire game to actually get a size 10+ city to grow 3-4 points above its housing cap.

Suggested tweak: shift those values in the housing/growth table down a few rows.
0 or more: 100% (normal growth)
-1 to -3: 50% (half growth)
-4: 25% (quarter growth)
-5 or less: 0% (no growth)
This means that if you have food, your city will carry on growing normally until it exceeds the housing cap by 1. I would strongly suggest pairing this with a growing amenity hit for being over your housing cap: people don't like living in overcrowded cities. The rent is too damn high
Now you're suddenly going to be confronted by populations that are constantly creeping up to the local carrying capacity - and neighborhoods have a big place in the game again.
Shotgun concept: introduce some kind of yield penalty for being over the housing cap. Nothing awful, but representing the historically unsanitary nature of packing people in like sardines. If only cities could build some kind of underground sanitation network to alleviate it... Oh, look, the Sewer building could also eliminate that penalty. Suddenly there's a compelling reason to build those pricey sewers again. (though one could also tie this into the Aqueduct district.)

Civ IV had cottages that increased in value but didn't actually reflect pops, I think. Civ VI has neighborhoods in late game which do actually allow for pop increase. I would think having the cottage mechanism leading to neighborhoods(suburbs) in later game would add interesting facet to Civ VI. Allow the cottage to allow 1 additional pop, village 2 and neighborhood 3 or more, as well as generate gold.

One of my first threads proposed that very concept! Some of the game changes in R&F have changed the housing game a bit if you focus on it, but I still believe that gold is too tied to how many CHs you have, and not enough to terrain - we end up with this gameplay where everything that isn't a district is a farm or mine. Cottages could bust that up a bit, especially if bigger cities had to have them.

 

[acluewithout]

@Sostratus That's a really good idea. Particularly folding into it some sort of happiness issue if you're over your housing. Elegant.

It might need to be combined with some overall curb on growth in later eras - growth of advanced societies seems to curb at some point as people start having families later and having only one or two kids.

*** Actually. Thinking about this some more. Would this really solve the problem entirely?

The reason we don’t get cities “bursting at the seams” is that the player controls growth. Adjusting housing would make it easier to grow cities - but nothing changes if players wants to and can avoid growth. They’d just not work farms etc.

You either have to force players to have big cities and or make high pop cities more valuable (currently the only value is a few eurekas and maybe boosting production if you’re not going for a chop heavy strategy and not finnishing the game with low turn times).

I’m not sure much can be done here without massively complicating or changing the game. But some (half brained) thoughts:

- What if districts and your government tier provided additional food to the city centre? The idea would be that cities “grow” (get food) reflecting people moving to this city because it’s more developed. So, if you develop a city, expect it to grow.

- What if your capital received additional food based on your current government tier, reflecting people moving to your capital?

- What if all cities received food from incoming trade routes?

- What if 10+ population cities gave you trade routes? This could be in addition or in place of markets etc. providing trade routes.

- What if high pop cities received a +% to certain yields? So, a 10+ city would inherently produce more science per citizen.

- What if reaching your housing gave negative amenities, but sewers (in addition to housing) also “cancelled” this negative amenities. So, provided you had sewers, your city could get to their housing cap without everyone being miserable.

The only way I can ever see this all being “better” is if growth was driven not by food but by something beyond the players control.

So, eg

- your cities would grow based on you placing districts and buildings in the city, trade route to the city etc.

- You wouldn’t build farms any more, instead your city would randomly convert some tiles to farms (which you might build over later).

- You’d suffer negatives if your pop reached its housing cap (although that might still slow further growth), so you’d have to build Neighbourhoods etc. reactively to remove these negatives, but that would just cause your cities to grow more, repeating the cycle... Or, you’d have to build settlers to lower your population (or perhaps at some point your city “insists” on building a settler “we’ve had enough of this... let’s go start a colony in the new world...”).

- At some point in the tech tree, growth would really boom and housing would stop being an issue. But you’d also have a tech that stops the negatives from overcrowding, so at that point big cities would be more stable.

- Really crazy idea. What if cities at their housing cap had a % chance of “disease”. This would prevent the city producing anything for a number of terms and reduce the cities population. This cycle would potentially keep repeating until eg the Industrial era or the sanitation tech. In the meantime, you’ll want to keep an eye on housing.