How to manipulate population age distribution?

[Stringer Bell]

Sorry for this long post -- it's maybe a little technical so bear with me, but I have been trying to figure out how this game works and am exhausted I think I should probably ask around instead.

Something I've been noticing with my city lately is that the population fluctuates dramatically (it has always fluctuated which I think is normal but lately it's going nuts and it gets worse if I leave it unattended) -- I have been trying to remember what I did, but possibly zoning additional residential areas at the same time and/or replacing a bunch of L5 residential buildings by plopping instead of letting it grow from L1, so that new occupants moved in en masse instead of gradually and spreading out the age distribution.

My deathcare and traffic, etc are all working fine, so it's got nothing to do with it actually messing up my city, it's just that it's driving me a little nuts that my population can go from 340K to 260K and my treasury can go from +250K a week to -250K a week.

I've been doing a lot of research and trial and error and right now I think I have a general idea about how to fix it (and has fixed the problem to a degree). Like I just have a vague idea and it is not precise and I really am tired of spending hours trying to figure out the mechanics of this game that seems buried and not accessible to players, and figure I should just throw this around.

I guess more specifically, my questions are:

(1) If I do not want to expand my city any further (since it is hitting dangerously close to some object limits) which means I need to fix this by demolishing (i.e. new building rebuilds immediately) / dezoning (getting rid of current building and wait for the right time to rebuild it) residential areas, what is the best strategy to go about this?

(2) Right now I think my logic is that when I see that death rate and birth rate are similar, then the population age distribution is in equilibrium, but then as these rates start dropping / skyrocketing dramatically, that means something has to be done at the right moment or moments of the CIMs' life cycle to destroy / plop / dezone / rezone a bunch of residential areas (in gradual batches presumably to spread it out). I just can't figure out what the time is. It's like when the birth / death wave hits, you are already experiencing the bubble bursting. I want to know precisely when the bubble starts building and it's really hard to figure out.

(3) So right now my birth rate and death rate as per the city statistic chart are like two waveform crisscrossing each other which makes sense given what is happening. My objective is to "dampen" the troughs and crests of each of this wave so they are closer to a flatline. And right now each "death / birth wave cycle" spans about 2.5 to 3 years, which makes sense given the lifespan of a CIM is allegedly 6 years. So in essence, during the lifespan of each CIM he or she will be a part of two birth waves and two death waves:

(A) I allowed too many adults to move in at the same time at one point and they all have kids at the same time (1st birth wave);
(B) Their parents grow old and die (1st death wave);
(C) These kids grow up and become adults and all at the same time have kids (2nd birth wave);
(D) They themselves grow old and die (2nd death wave).

The thing that is confusing is that the population change you see in the menu bar does not reflect the difference between the birth rate and death rate. My population starts dropping long before the birth rate falls below the death rate, and the same goes for when the population starts rising again, the death rate is still way higher than the birth rate and it stays that way for quite a bit. So there is this unknown element of people migrating into / out of the city, which again is just not a piece of information a player has access to.

(4) I have been checking out the colored pie charts of buildings to determine the age distribution before I destroy it or leave it alone. But the thing is, I am not sure what the pie charts "really mean" -- should I get rid of a building with a lot of seniors during a death wave? I notice that if you do that, the seniors are basically gone, but do the adults stay in the city and just move to another building? Or do new adults move into the city to take their place? And if I tear down a building with a lot of seniors when a death wave hits, isn't it already too late? I imagine I should really replace a building with a lot of adults that have just started aging with a new building so "fresh and young" adults will move in and thus delay and dampen the cycle. But how do I get that information from looking at the pie charts (or as a matter of fact anywhere in the game)? Further complicating the matter is that there are both high residential areas and low residential areas and I don't know if CIMS move between buildings -- they probably do, and it just makes the whole pickle even harder to crack.

Sorry again for this long-winded post but any help will be most appreciated. THANKS!

[grapplehoeker]

To save typing, here are a couple of guides that should help make sense of it all ;)
https://steamcommunity.com/sharedfiles/filedetails/?id=425513385
https://steamcommunity.com/sharedfiles/filedetails/?id=578759936

[Markus Reese]

Heyo! Your answer to your question is a longer and more complex issue. Fortunately got a link to a post written the other day!

https://steamcommunity.com/app/255710/discussions/0/1639790664931472290/#c1639790664933535116

You didnt plop your city all at once, so why does it happen city wide? What you have is a death resonance, when your city starts to sync up. It starts small, but gets real bad. Then your services prioritization and pathfinding breaks, and mass exodus. Tiny zonal seeding can help prevent it from starting, but it isnt the cause.

Read that post. Low density residential areas, spread of services, and good service access are the keys to prevention. If you have too much high density or need to fix, reszone areas to low density to help relieve stress and get population stratified again.

[Stringer Bell]

Thank you for the responses and advices!

@grapplehoeker I have stumbled upon the first guide you posted when doing my research but the second one I haven't seen, and it is an interesting read. I am gonna test it out by zoning residential once seniors exceed 20% and see what happens.

It actually led me to look at my unemployment rate -- before I thought it's got nothing to do with birth and death cycles --> again it's frustrating how these intricate relationships between different numbers are largely unexplained by the developer and just left for players to blindly try to figure them out.

The funny thing is I noticed now that my city of about 300K population, there are 160K jobs (after I dezoned a bunch of office areas following the guide's advice to leave demand for industries/office zones high) but only 131K people are employed but at the same time the unemployment rate is close to 20%. It's like there are all these free jobs floating around but no one is taking them and people are just opting to stay unemployed. FYI I do not think it's because people are not educated enough to take them, a lot of them are just factory jobs and 90% of the office buildings I clicked on have 0 jobs available, and the other 10% have 1.

I'm wondering if I am over-zoning industry / office (even though demand is high now, as suggested by the 20% unemployment rate). I remember when the city used to be smaller, the jobs available number is very close to the people employed number, and the difference is in line with the unemployment rate, now it seems off.

@twistedmelon -- thanks for the advice but I think by "death wave" I actually don't mean crematoriums not picking up people in time resulting in the skull icon. Every body is taken care of and I do not see any alerts. It's just that the population of the city fluctuates greatly (+/- nearly 30% every 2 years) it messes with my school budget and education level of citizens, etc. I tend to believe it's got more to do with CIMs life cycle and how death rate and birth rates are out of sync at the moment and I am trying to find a way to bring the out of sync crests and troughs closer to a flat line.

[Markus Reese]

Well, the birth and death out of sync a little. But shouldn't be huge spikes like that Only seen with death waves of skull covered maps. Have a solution to try at end. Mid part is just filler on reasoning.

Do you have mostly just high density? This was something brought up by the devs a while back about the differences between the high and low density for residential and commercial and how they meet different needs. Industry produces goods while offices act like a service. Commercial has different levels of attractiveness, requirements and the needs they meet.

Residential is the overlooked one. Many don't think about the age spread in the cities. Low density promotes more youth than high density. There is a cycle that the game wants. New families want low density. This encourages them to create youth. young adults and adults want to go to high density til they start families.

The people that move to the low density get old and die, then new families move in. Some become seniors in high density.

If you don't get this cycle, then you an sort of end up locked. If you have a lot of high density, you start relying more on immigrants..... Hard to really explain what I mean and not doing it very well.... Essentially old people tie up residences needed for new families. So when they die you get a spike in birth and they can sort of sync up....

This is just observational and based on past info from devs. Essentially apartments are locking up population when they become a group seniors care home. When they finally die and free, mass of people looking for home move out and burst of babies. Cluster of new similar age youth. Could be keeping up with death care, but the combination of emigration and limited space for people to move to is making it all age matched.


TL:DR, if you have mostly high density residential, rezone some of of it to be low density. It will give you a supply of youth to as well as places for people to move so they don't tie up the high density. Give that a try.

[grapplehoeker]

Originally posted by Stringer Bell:

It's just that the population of the city fluctuates greatly (+/- nearly 30% every 2 years) it messes with my school budget and education level of citizens, etc. I tend to believe it's got more to do with CIMs life cycle and how death rate and birth rates are out of sync at the moment and I am trying to find a way to bring the out of sync crests and troughs closer to a flat line.

Your % of seniors is around 24% and 24% of 300k is roughly 75k, so do not be concerned if you see fluctuations to around this figure as it is just the normal pulse of the population lifecycle.
You should see it rising by 75k too as the population regrows again due to influx and new births.
Only pay attention if you see a lot of sickness and deaths of more than 75k as that would be unnatural and a tell tale sign of a pollution/poisoning event.

[feigendelta]

I've used the mod "citizen lifecycle rebalance" and never looked back.

https://steamcommunity.com/sharedfiles/filedetails/?id=654707599

[Markus Reese]

But.... that is a mod.... be boss, do it no mod! Though that said, it doesnt make sense all people moving in are the same.

[Stringer Bell]

Thanks @twistedmelon and @grapplehoeker!

Yeah, still haven't been able to resolve this, been trying all kinds of different zoning and waiting for game years for the effect to kick in but still no luck. Tried decreasing amount of jobs / increasing amount of jobs / decreasing residential zones / increasing residential zones / rebuilding (i.e. bulldozing and plopping) residential buildings at the right moment supposed to cancel our spikes, etc. No matter what I do, after a while the same rise and drop pattern just comes back and I still consistently have a 50K to 60K fluctuation which is kinda frustrating.

About the unemployment rate, the people employed vs jobs available percentage only goes between 70% to 80% (adding / reducing workplaces doesn't seem to have an effect, the same percentage remains even if there are more / fewer jobs). Is this normal? It's like people are moving out of my city (and they are all educated, so it's not like I only have high-end jobs that lowly educated people can't fill) while there are still jobs floating around.

I am trying to play this game without "cheating", but are there any mods which can let me look at numbers that can help me understand better what the problem is?

And about low vs high density residential, I think I have enough low residential zones (basically my city is surrounded by suburbs made up of low residential). Also traffic is not a problem my traffic flow is consistently above 78% and sometimes reaching 84%. There is no backed up traffic, just a bit of congestion at critical junctions.

[bgnewhouse]

The Citizen Lifecycle Rebalance mod might help you:

https://steamcommunity.com/sharedfiles/filedetails/?id=654707599