"Due to popular demand, here's a little more information
on the population growth (and death) rates and maximum sizes, courtesy
of Tom Hughes' economic model efforts."
1. Population Growth
2. Population Starvation
3. Maximum Population Size of
5. Economics of Population Points
Population growth occurs automatically and is calculated per population
center (=a region that has any population on it at all). It's based
on several factors:
Environment, Racial Tendencies, Growth Enhancing/Restricting Events
and Technologies, etc.
The basic growth formula depends upon
A the current population of the region
B the race's base rate of growth in the region, and
C the maximum population of the region.
Population growth occurs most quickly when the region
is neither too empty nor too full. There are two formulas that control
growth - click here.
When half or more of the food requirements are met, the population
is merely "hungry" and their growth rate is reduced proportionally
to the level of food shortfall. Thus, with exactly half the needed
food coming in, there is a 0% growth rate on that region.
When less than half the food required arrives, then
the folks are "starving". This gives that region a "death rate"
to worry about instead of a "birth rate" because people are dying
faster than they're being born. The death rate proportionally increases
with the shortfall of food up to five times what the opposite of
the maximum growth rate for that region would be.
That is, on a 1% to 5% scale, if people were growing
at 1%, they'd starve at a five times 5% rate and vice-versa. ->
The more people in a region, the faster they'll die off.
The main factor that determines how many Population Points maximum
a region can hold is the size of the planet.
It is also modified by the Habitability Zone that the planet resides
in and the Ecosystem Density of that region.
here for details.
When a planet isnt habitable to a race, the population there
must live in a controlled (or "enclosed") environment
dubbed a "biosphere".
Every population group residing on a planet that is in that species
Yellow 2 or Red Habitability Rings is considered living in a biosphere.
A The greatest drawback to biosphere living is that
maintenance costs for that population group and any improvements
in that region are exorbitant.
B The population group living in a region of the outer
yellow or either red habitability ring must import all the food
it eats. There are two Technology Achievements that ameliorate this
- "Bio-morphic Fungi" permits bioharvesting by one additional
- "Mineral-morphic Fungi" permits bioharvesting two
additional Habitability Rings.
When a civilization has both of these, therefore, it can bioharvest
all the way into the outer Red Habitability Ring. In addition, Hydroponic
Farms and Subterranean Farms are fully functional in biospheres.
They add +½ and +1 unit of bioharvest unit each turn, respectively,
even when placed in a Bioharvesting DEA that is built in a biosphere.
C No population will voluntarily move to a region where it will
be living in a biosphere. That is, no migrants, immigrants, nor
pioneers will settle there. If a civilization wishes to establish
population groups in a biosphere living conditions, they must be
brought over in outpost and colony ships and deposited there.
D Population living within a biosphere environment can grow naturally.
Usually, such population groups grow at the rock-bottom (1%) population
E On top of everything else, the maximum population limit for a
region requiring biosphere living is only 1 Population Point. There
are two Technology Achievements concerning the maximum population
limit of a civilizations biospheres.
- Biosphere Housing Management (+0.33)
- Biospheric Urbanization Module (+0.67)
In addition to their primary role (=serving the labor needs of a
planets economic capacity) each population point produces
3 Cement units and 1 Test Tube unit per turn. Click
here for details (formulas for each population point).
Population points do not directly generate money. Instead, the value
of all the goods they produce that do generate pre-tax income that
is computed into that planets Gross Planetary Production.