Population Growth Help

[jgbrowning]

well

How do you figure numbers as low as 3 children per woman?
They are specifically trying to build their population and each woman is going to have @ 20 years to bear children. It should be more in the range of 10 - 15 per woman which was typical among rural farming families. The population should explode if you have no external limits keeping the numbers down.

considering the population of germany only quintupled in 700 years... assuming that the author errors enough to allow a sextupling and asuming that magic triples (generous, i think) the overall rate, that would leave a x18 growth rate for 700 years in a fantasy medieval environment. (all of this is on average of course).

lets be generous and say the guys population would x9 in 100 years if they're trying hard. so he'd end up with about 1250 people.

if the town happens to have a good location for trade (the source of town growth) it could of course grow more than that, but from his discription it sounds like it would be more of agrarian/independant development.

joe b.

 

[Umbran]

It should be more in the range of 10 - 15 per woman which was typical among rural farming families.

You got that from a reliable source? If so, please name it.

While women who can manage to bear 10 kids are known, they are pretty rare. The stress of childbearing is rather high. And the risks of having so many children without modern medical attention is considerable.

 

[CRGreathouse]

There are many answers. Most come down to a simple growth rate, some consider limiting factors, but some are completely different.

For example, a Fibinacciesque model (originally designed based on rabbit reproduction rates) would give

21, 42, 63, 105, 168, 273, 441, 714...

 

[The Onion Knight]

Re: well

Hey douche bag
he stated some limits on his population, one being that there were no population shrinking events (no plague, famine, major wars) in the time about which you mentioned in Germany that nation had undergone 2 major plagues (one reducing their total population by 2/3), one major famine lasting 100 years (plus a few others lasting a considerably shorter period of time ) and at least one major war lasting 35+ years. Take a history class why don't you

considering the population of germany only quintupled in 700 years... assuming that the author errors enough to allow a sextupling and asuming that magic triples (generous, i think) the overall rate, that would leave a x18 growth rate for 700 years in a fantasy medieval environment. (all of this is on average of course).

lets be generous and say the guys population would x9 in 100 years if they're trying hard. so he'd end up with about 1250 people.

if the town happens to have a good location for trade (the source of town growth) it could of course grow more than that, but from his discription it sounds like it would be more of agrarian/independant development.

joe b.

 

[Kal Torak]

The figure of 10 or 15 children per woman is far to high, considering a "normal" child mortality rate of 50% (and it could be higher!) that would meen a woman giving birth between 20 and 30 times!!!!!! I think that a total of 8 times is already quite high, specially considering dying in child birth (a very common death for wemen in the middle ages). But I have found the problem with my prevoious figures, 21 women of child bearing age, not people.
So we consider a starting number of 42 and double it every 15 years. With a life expectancie (sp?) of 60 years you get the figure: 1400 (circa) + about as maney children (if not more).

 

[Umbran]

Onion Knight:

Unfortunately, you seem to need a course in manners more than others need one in history. No matter how technically correct you feel you may be, the name calling was uncalled for. You owe jgbrowning an apology.

 

[jgbrowning]

Re: Re: well

Hey douche bag
he stated some limits on his population, one being that there were no population shrinking events (no plague, famine, major wars) in the time about which you mentioned in Germany that nation had undergone 2 major plagues (one reducing their total population by 2/3), one major famine lasting 100 years (plus a few others lasting a considerably shorter period of time ) and at least one major war lasting 35+ years. Take a history class why don't you

Lets look at what the original Poster said:

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"I need some help for something I'm working on. I need to know roughly how much a population would increase in 100 years, from a base of 138, with 21 viable child-bearers. The colony has good resources, no immigration, and little attrition. I'm not good with the required math. Thanks in advance.

Many of the original population will die of old age with a couple of decades. Women are considered ready for bearing children at 14-15. As a whole, the people are concentrating on increasing their population, using the "it takes a village" idea, so the women are encouraged to have as many children as possible until their bodies just can't do it any more.

Except for the older folks, the level of health is pretty good, but they lack clerical spells to remove diseases and such. There really is no way of reducing infant mortality. The land is good, near a body of water, with room to expand, , and capable of supporting a large population."
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ok, how do you get "no population shrinking events (no plague, famine)" from the original poster when he says there is no magical way to remove disease and there is no way of reducing infant mortality? do i need to make my case that just because a location has "good" resources doesn't mean it will "never" have bad harvests?

you want the facts about infant mortality in the middle ages? the usual number is 30% (up to 50% has been speculated). about 50% of the people who survived infancy didn't make it out of childhood. of those that became adults most didn't make it past 30 years. without magic, there is no reason to assume different results than what occured, in general, in history.

To Danzig 138: if you want to make assumptions that the place is lucky and fruitful and has no wars or fighting with humanoids/monsters, cut down those numbers some and increase average life expectancy.

joe b.