Increase planetary fundings?
I've been playing as the human race. I don't seem to be able to figure out how to encourage population growth. In every game I've played, at about turn 150 none of my planets have more than about half their maximum allowed population. I tried building a Bioharvest DEA, but haven't had much luck. The manual says you need a moderate population to run it. What is a "moderate" population?
Does anyone have any suggestions for encouraging population growth?
Increase planetary fundings?
Try migrating your population to those small colonies, this would keep your populated worlds free to produce more civilians. To do this, go to planets, find a planet with a low ratio of colonist, go to orders below (the second tab), and click "Migration".
I did an experiment to boost the productivity of home system industry world. My home system has 3 worlds, one of which was my Home and two colonies. The two colonies were founded apx 7 turns apart so their pop was about the same. I Set Migration to the industry planet. The result was amazing. The industry world had a pop of about 23 (eventually) to the other colonyís 8, and the size 8 colony was established first.
I think the key here is two things. First, the growth rate of starter colonies is very small (say 0.15/turn). Emigration seems to vary based on the size of your emigration world, but your early capital should give 0.15/turn (much more later). This doubles the growth of the target world, and lets it get to the superior growth rate of a world with an established population (about 0.25 to 0.30/turn). Second, your pop of your capital doesnít get into the high zone at about 75% max, and this causes unrest.
There are negatives, primarily that you are limiting your capitalís growth. But, Iíve decided that after about 1 pop/DEA you might be better off emigrating so you can utilize the DEAs on other planets.
Any other opinions or observations?
Well, it took me an embarassingly long time to work this out, but then the underlying game mechanics are a little opaque. DEAs all take some amount of population to run (the manual provides some info on the relative but not absolute amounts) and the improvements which you eventually research (e.g. Deep Extraction Mining) add to the population requirement to run that now improved DEA. You have two numbers on the right hand side of the planet screen (which tell you basically the same thing in two formats) which are critical to the efficiency of the planet. The first is DEA Employment. Say it is 6/12; that means that the DEAs you have on your planet require 12 Pop points to run and the current Pop is 6. The number below it will be 50ish% - which means that all your DEAs are operating at around 50% efficiency, e.g. providing half their rated output. However, if your population exceeds the minimum requirement, you will overdrive the DEAs and get more than 100% efficiency. You do get diminishing returns on this, but I don't really know how quickly or how sharply. For those industrial worlds that are going to be the backbone of your military production, you should always try to get the pop above the 100% mark and emigration/immigration is the best way to do it. I do wish that I could put a 'lock' on some planets to prevent emigration from them. AFAIK, pop exodus will be proportional to high pop/low desirability and ingress to low pop/high desirability (if you have multiple destination planets selected).
So, to increase overall population growth of your empire, you need to colonize green large fertile planets, and keep low (CurrentPopulation/MaxPopulation) on each planet.
Techs for faster PopGrowth:
Direct: Cloning Complex (B13), Smart Drugs (B25), Antiagathics (B38).
Indirect: all terraforming techs - better habitability ring of planet, fertility of regions, max population of planet - Sunlight Redirection (C10), Magnetic Field Modification (M18), Atmospheric Containment (B25), Climate Controllers (M31), Planetary Core Heat Pumps (E36), Atmospheric Processors (C41), Bio-Engineered Life (B45); incr. max pop. - Residential Metroplex (C14, S14), Mass Vertical Urbanization (S34, C31).