Greetings, I'll get right to the point.
The hard population cap is determined by planet size, as far as I know, as long as you can build enough cities to reach it. However, I have a superworld here that is rapidly reaching 20 billion souls, and they are getting quite arsey down there. My morale is deep state rouge at 25%, the entertainment centres are about as much use as a squirrel fart in a thunderstorm, and I dislike wasting hex spaces on morale buildings anyway. How do I get this mess under control? And what's the optimimum amount of people you should have on a world anyway?
Cheers.