A problem I've encountered (I mentioned this in the "How does one make babies" thread) is that once immigration has filled up all the houses, there is no new blood. For some reason a cycle of evolution and/or devolution may be enough to allow babies to be made, but this stops after 30 or 40 years or so, and all people do is get old. After they exceed the age of 60 they stop working, and when the labor rate is low enough the city starts to fall apart (this happened with my city at th 37 year mark, with a labor participation rate of 11%).

Another problem is that after Egyptians reach the age of 100 they are no longer counted by the census. They continue to eat food, devolution won't kick them out (you have to demolish all housing), they don't count towards entertainment coverage... they are non workers, so after a while they seriously start to impede the smooth functioning of a city.

I've had success in making houses go through cycles of evolution and devolution. 30 squares of housing at rough cottage has a population of 390; a bandstand (without entertainers) gives a city wide bonus of 10 entertainment points when the population is under 390. Thus the rough cottages all evolve to ordinary cottages, which attract immigrants, which raises the population above 400, so the cottages devolve again, expelling a bunch of residents and starting the cycle afresh.

Egyptians under the age of sixty seem to be most susceptible to being kicked out when houses devolve, but it seems that a rapid cycling of evolution will eventually purge the city of all oldsters, and helps prevent centenarian immortals from filling up the place.

Yet a few managed to sneak through; after 20 years or so I checked on the city and saw 30 squares of ordinary cottage, no room for new immigrants, and a total population of 390; not the 450 that 30 full squares of ordinary cottage would indicate. The cycle of evolution and devolution had stopped, and there were no new births.

I tried a different tack. A city with less than 300 population has a sentiment of indifferent (pleased if less than 200). I provided entertainers for the venues, set taxes and wages to 15 and 38, and built enough industries so that there would be high unemployment (20-25%) when the houses were all full. I set it going. The houses evolved to pre-courthouse, and then the people would get annoyed at me and then angry. They would start to leave, and when the city population dropped below 300 they become indifferent. Immigration started up again, and the cycle began again.

This seemed to work extremely well in clearing out oldsters. Even toddlers and young people were in short supply. In fact, I once achieved a labor participation rate of just above 50%! No-one was over 60 for the 17 years that I ran the city.

But I got bored, and thought I would try to make the houses all 2x2 (so they would consume less resources and be more efficient). So I added a courthouse and a school. They all evolved to 2x2 common residences; 7 of them. I wandered off.

When I got back after several years, I noticed they hadn't devolved/evolved in a while. The city sentiment said something I had never seen before: "You are universally loathed because wages are too low."

I thought, "Well, why don't you leave the city then?" and I dropped wages to 0 and bumped taxes to 25%. (By the way, you can do this until the city population is over 300 with no effect at all on sentiment) Well, sentiment didn't change (I guess universal loathing is the worse you can get to) but nobody left the city either. The population stayed at 505. Now there were 7 common residences, with a population of 80 each, and I checked each of them. 6 were full, and the seventh had 72 residents. For a total of 552. So some centenarians had snuck in somehow, I don't know how.

But they still wouldn't leave.

They stayed, and they aged, and after a while city wide unemployment started to be a problem. I wandered off again, and when I came back fires had broken out and buildings had collapsed and everyone was dead and/or gone.

I reloaded from when I had dropped the wages and bumped the taxes (has anyone ever achieved this level of tyranny?) and eliminated scribal school and courthouse. 6 months later the houses devolved, people were angry at me and left, all as expected. The houses didn't devolve to 2x2's; lots of them were one by ones.

It is a very curious phenomenon, wouldn't you say? Perhaps some of you aspiring tyrants can experiment with similar cities, and see if a small number of residences can be cruelly mistreated without their residents leaving.

--Jimhotep