A player may wonder whether a city has enough vacancies to get all of the births that it could. The answer depends on demographics. To make the analysis simpler, I'll assume that each house that starts with vacancies has more vacancies than the minimum number of newborns per house. With that assumption, a city gets all of the births that it could when the number of houses that start with vacancies is at least as large as the maximum number of births in an age group. Note that deaths create vacancies, so a city with deaths may need fewer starting vacancies to get the maximum number of births.

In a new city, with demographics similar to that of typical immigrants, the 20-29 age group will have more than half of the births. Therefore, to get all of the births possible, there will need to be enough houses with vacancies so that some (a third might be enough) have only 1 newborn. As the city ages, the 20-29 age group should have a lower fraction of the births, and I'd expect that eventually the city would get the maximum births when all houses have at least 2 newborns and a few have 3, at least for a while.

It seems to me unlikely that a real city will get the maximum births when most of the houses have 3 newborns. A player who artificially modified the census could create a city where the maximum births occurred even when some houses have 4 newborns, but I wouldn't expect that to happen with an unmodified city.

Thanks Brugle for your research. I guess this was one of the few remaining things we didn't know for certain. I'm glad my initial research from years ago wasn't too far off.

I don't know if there will be any practical use of this information but at least it helps to understand what happens to a city's census over time.

If I understand correctly, any Caesar 3 city will eventually have a partially flattened census graph as long as you wait a few hundred years and the city health is between "almost perfect" and "below average".

I think now that we have the death and birth rates we could take any city with full houses at any year and calculate what the census will be in the future and how it will look like eventually.

After nearly 4 years of disinterest I have suddenly been possessed of the urge to rebuild my Fishopolis and came here to refresh my memory about a few things. Since a high number of births in the final year is crucial I was pleased to come across this new (to me) information. I was aware of Philon's earlier claims on births but to be honest I had doubted them. How close to the mark they have subsequently proved to be! The really useful discovery though is how births are allocated.

My city will have nearly 1500 houses at Small Casa. They will be supplied with a one-time delivery of pottery but they will only be given bath-house access at the last minute (the import quota on pottery is nowhere near enough to sustain a supply).

Looking at an old Fishopolis save I had 14357 in the most fertile band suggesting that even with so many houses I am losing considerable opportunity through lack of vacancies. If I am understanding correctly I should be able to increase the number of births by manipulating the census so as to have a much higher proportion of those demographic groups who typically generate lower birth numbers. Ideally I would aim for an equal number of births from each group. Is this understanding correct?

Manipulation would have to begin 50 years in advance. Initially health would be kept low to boost the numbers of those who will eventually form the 40-something group, then raised a little for a ten-year run, then raised quite high for ten years before being pulled down again to boost the future 10-19 group.

By the way, season's greetings to all. Great to see Brugle's still here with his encyclopedic knowledge

[This message has been edited by Trium (edited 12-26-2017 @ 08:37 AM).]

Hi Trium, it's great to hear from you.

Ideally I would aim for an equal number of births from each group. Is this understanding correct?

I don't think you can get enough births from the low-birth groups, and you don't want to cut the births from the high-birth groups to less than the number of houses. Other than that, it seems to be correct (assuming that the original post is correct).

Thanks Brugle. You're right, with 1500 houses I'd need 75000 people in the oldest group and 50000 in the youngest. Not possible at all. But I only need a little under 9400 20-somethings and under 17000 30-somethings so if I can squeeze those groups (without going lower than those limits) while at the same time encouraging more of the other two groups I should come out on top.