# Population Management

In Stars!, planetary population growth is affected both planetary value, and the percentage of the total population capacity present on the planet. In order to maximize your economic growth, it is necessary to move population around. What's the best plan? Once again, Jason comes through with the goods!

Subject: Re: Early Population growth: rules of thumb

Date: Fri, 15 Jan 1999 22:16:48 GMT

From: {email removed by editor}

Organization: Deja News - The Leader in Internet Discussion

Newsgroups: rec.games.computer.stars

In article <369F326A.87C65946@mckinsey.com>, {email removed by editor} wrote:

> To finally get it right: > 1. Do I maximize increase in population from one specific planet by > keeping its capacity as close to 33% as possible ?

Yes, you do. 33% gives the most pop growth per planet.

Aside - Not that that is always the thing you want to maximize - often it isn't. For instance, 50% or so can wind up giving more resources over the whole period until the planet is filled, if you are using an orbiting freighter fleet to fill it - takes a bit longer, but you get more on the way. If you only maximize pop growth you can wind up hurting your overall econ performance sometimes (fewer factories operated, or for less time, or more pop resources "lost in space", etc).

> 2. Do I maximize increase in overall population of ALL planets by > 2.1 first filling homeworld to 25% and then

So far so good :-)

> 2.2 continuing to fill homeworld unless there is a planet for which: > Planet Value*Max.Growth rate > Current Growth rate of my > homeworld ?

No. This isn't right. See, you don't kill all your homeworld growth when you move some of its pop somewhere else. You get both the growth on the HW (at some hold level) and the growth of the pop elsewhere (with some amount having been sent, that amount being higher with a lower HW hold). So you aren't trading the HW growth for the other world growth (if you were, then your 2.2 would be right, but it isn't). You are trading the HW *marginal* growth (the change in HW growth because of the last bit of pop, the bit you are considering moving) for the *marginal* growth on the other world (how much the growth on the other world would change if the moved bit of pop where there).

To see this, imagine moving pop over the 33% level. The HW pop growth is not going to go *down* because you move that, it is going to go *up*. You are relieving crowding. But *any* green world under 33% of capacity, that same pop would grow *some*, thus a positive "marginal".

If the alternate *habitat* is 33% or better and uncrowded (under 25% of capacity), then (ignoring travel time) you will get the most pop growth holding the HW at *25%*. 25% gives more pop growing on the decent worlds (inputs), and thus more compounding overall. The reason for the 33% hab figure is that the marginal growth of the HW pop drops by 2/3rds as you cross the 25% line.

Note that just in pop-maximizing terms, the above is *always* true for IS races, since they have 50% habitat available if they can buy freighters to hold the amount of pop.

If the alternate habitat is *0%* (or yellows, or very long travel times) then you maximize the pop growth holding the HW at *33%* (since when the moved pop doesn't grow, the maximum growth happens with whatever maximizes the HW growth).

Between 33 and 0 alternate hab, the exact best place for the HW will be between 25 and 33, but the differences are going to be tiny and temporary.

I recommend using 25% on the HW until all the factories the population can operate at that hold level are done. Then let the HW grow to 50% (to get the "resource integral", not the pop growth - as per the first aside above), then hold it again. That is simple and will get you close to optimal performance; since there are trade-offs of things like pop growth/developing time vs. resources on the way and such, close is good enough - optimals are something of a chimera. You can wind up getting more of what you are aiming at but less of other things that also matter if you just maximize pop growth.

The most important thing is not to let the HW (or other good "breeders") get very crowded (over 50% of capacity or so) before you have hit all the places you want to live. In the case of the non-HW breeders (since those you don't get he HWs special mineral non-depletetion, which is a seperate incentive to fill the HW to capacity) leaving them at 50% until all other space is filled is a good idea. And 25% is the proper hold for the HW early on, when the HW pop would not operate factories right away and there is good alternate hab available nearby.

I hope this is somewhat clearer than mud.

Sincerely,

Jason Cawley

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