Population

Hi All,

Does anyone have a suggested read for population trends?

I've done some basic calculations for a population increase of a colony of 1000 souls, assuming that this is 500 couples, and that each have 5 children that survive to adulthood (this assumption based on an average, as some woudln't be couples and some would have less children, but others would have more) we end up with something like this (each line is a generation:

1000
1500
2250
3375
5063
7594
11391
17086
25629
38443
57665
86498
129746
194620
291929
437894
656841
985261
1477892
2216838

I'm likely to have the numbers wrong. The calculation is correct (I've taken death of the parents into account etc) but any suggestions would be appreciated.
 
Hi All,

Does anyone have a suggested read for population trends?

I've done some basic calculations for a population increase of a colony of 1000 souls, assuming that this is 500 couples, and that each have 5 children that survive to adulthood (this assumption based on an average, as some woudln't be couples and some would have less children, but others would have more) we end up with something like this (each line is a generation:

1000
1500
2250
3375
5063
7594
11391
17086
25629
38443
57665
86498
129746
194620
291929
437894
656841
985261
1477892
2216838

I'm likely to have the numbers wrong. The calculation is correct (I've taken death of the parents into account etc) but any suggestions would be appreciated.
Assuming they have animals you would almost definitely have outbreaks of disease, not to mention that the majority of children died before reaching adulthood (assuming you mean a medieval colony).
 
Assuming they have animals you would almost definitely have outbreaks of disease, not to mention that the majority of children died before reaching adulthood (assuming you mean a medieval colony).

Yes, that's why I said 5... and why I need help on trends. I think the children count in medieval times was around the 8+ kids, with MANY (I don't know if 'majority' is accurate) dying before reaching adulthood (so 5 left to breed).
 
if there are 1000 people, they'd probably be between the ages of 0-60 (assuming this is during a colonial age, most people older than that wouldn't go colonizing anywhere). so it stands to reason that 3/14s of the population would not be of an age where they can reproduce.

the calculation also doesn't take homosexuality into account, which is about 10% of the human population.
 
if there are 1000 people, they'd probably be between the ages of 0-60 (assuming this is during a colonial age, most people older than that wouldn't go colonizing anywhere). so it stands to reason that 3/14s of the population would not be of an age where they can reproduce.

I don't agree with the population age spread. Do you have any verification of this? I wouldn't have thought anyone other than late teens to early 40's would go colonising.

This is a separate part of my Norse in America thread, so we're talking Medieval


the calculation also doesn't take homosexuality into account, which is about 10% of the human population.

It does:

some woudln't be couples and some would have less children, but others would have more

My value may be wrong, but I've taken that into account.

So, I guess another way of asking is what would the average number of children to survive to adulthood with a starting population of 1000?
 
Another factor to take into consideration are societal marriage patterns. Contrary to popular belief, during the Medieval and Early Modern Period, surviving records indicate that the majority of people married in their late twenties or even early thirties, given that men needed to establish themselves as able to provide for a family and women often had to work in order to save up for a suitable dowry. This can significantly influence birth rates, as female fertility tends to begin to wane around that time.

Going through my notes on demographics in sixteenth and seventeenth century England, it is estimated by modern scholars that the average family size was 5 or 6 children, with about half dying before adulthood. Also, keep in mind, urban mortality is going to be significantly higher than rural mortality.
 
If it is Medieval age then, annual population growth couldn't reach 1%. So assuming colony is very favorable to live, I would purpose 1% annual growth until the land reaches overpopulation.
 
Another factor to take into consideration are societal marriage patterns. Contrary to popular belief, during the Medieval and Early Modern Period, surviving records indicate that the majority of people married in their late twenties or even early thirties, given that men needed to establish themselves as able to provide for a family and women often had to work in order to save up for a suitable dowry. This can significantly influence birth rates, as female fertility tends to begin to wane around that time.

I don't think male age has any real effect. The women would be marrying older men almost as soon as they could produce children and so while the initial stages of reproduction may be delayed by 10 or 20 years the children would still be being produced. Females would not be marrying their own age group... I think this is a modern problem.

Going through my notes on demographics in sixteenth and seventeenth century England, it is estimated by modern scholars that the average family size was 5 or 6 children, with about half dying before adulthood. Also, keep in mind, urban mortality is going to be significantly higher than rural mortality.

Thanks for that. I don't think I really need to worry about Urbanism until the colony takes off, but will keep it in mind - thanks.
 
Sorry, but your numbers don't make any sense to me. If you assume that 5 children survive to adulthood per couple with the parents promptly dying by that stage (I assume you equate a generation with 20 years or so?) then this simplistic model should give a trend of generational expansion of

1000
2500
6250
15625
etc

If 2 parents produce 5 adult kids and then the parents die that still means the next generation will see a population increase of 250%, not the 150% you have. Of course that includes ignoring a lot of likely realities but the basic arithmetical model you have used is wrong in terms of your explanation.

However, as someone else pointed out having 5 adult kids per family is unlikely, child mortality rates were higher than that. If you changed your hypothesis to 3 kids per family surviving to adulthood (yielding an average 150% generational growth rate) then your original numbers are correct. It's still highly debatable if those numbers are in any way plausible but it would at least be mathematically consistent.

Sorry to nitpick but your statement "assumption based on an average, as some woudln't be couples " does not hold with the idea that 1000 souls = 500 couples as that implies absolutely everyone is involved in a couple.

"I wouldn't have thought anyone other than late teens to early 40's would go colonising."

People tend to be sentimental about their families, they aren't going to leave the kids or dependent grandma at the dock when they board ship for their new world.
 
Ok, I'll re-check my calculations. I must admit that when I changed it to 3 children it didn't seem to work, so I've probably made an error somewhere.

People tend to be sentimental about their families, they aren't going to leave the kids or dependent grandma at the dock when they board ship for their new world.

I respectfully disagree with this. I think that you might be putting 20th/21st century sentiment into those not used to that kind of opinions. Dependant grandma isn't going to be able to make a journey on ANY colonial attempts. So those unable to leave grandma in the care of other relatives wouldn't leave. Babes in arms are also less likely to be able to make the journey. Yes, younger children (5+) would probably be able to make the journey, but babies would be at a very 'at risk' and so unless forced (convicts etc) would not volunteer to undertake that journey until the children were older.
 
Ok, I'll re-check my calculations. I must admit that when I changed it to 3 children it didn't seem to work, so I've probably made an error somewhere.

Ok, I re-did the chart. Interestingly the chart I originally made works for 3 surviving Children to adulthood.

I don't know how I did the 5. Totally weird.

Anyway - it works for 3 children, which is probably a better rate as discussed above.
 
If it is Medieval age then, annual population growth couldn't reach 1%. So assuming colony is very favorable to live, I would purpose 1% annual growth until the land reaches overpopulation.

I'm not 100% sure on what you're saying here. Just to confirm, you're suggesting that a colony of 1000 souls will be as follows for 10 years:

1000
1010
1020
1030
1041
1051
1062
1072
1083 etc?

If so that's pretty slow. I'm not saying you're wrong, but it goes against my intuition. If so (and unless my calcs are wrong) after 380 years you're only at a population of 45,000. Again, my calcs could be wrong, or I could be misunderstanding your suggestion - or I could be getting you right and you could be 100% right.
 
"Dependant grandma isn't going to be able to make a journey on ANY colonial attempts. So those unable to leave grandma in the care of other relatives wouldn't leave. Babes in arms are also less likely to be able to make the journey. Yes, younger children (5+) would probably be able to make the journey, but babies would be at a very 'at risk' and so unless forced (convicts etc) would not volunteer to undertake that journey until the children were older."

I suggest you take a look at passenger lists of ships bound for the New World. For example, the passenger list of the Mayflower shows a large number of children were on board. Many died within a few years, but they were on board, and a proportion survived to a ripe old age. The Mayflower passenger list also shows you are missing a crucial segment of society, servants. People took their servants with them, and servants were often children, while even adult servants and indentured labourers usually were not free to form families. That will throw your calculations out a bit.

As for the elderly never going, that just didn't happen. Again, mortality rates for the elderly were high but they did travel to colonies (saying they wouldn't just was not the case) and a number survived. That will change the numbers some too.

Is your model assuming that there are no further shipments of people to a colony once it is established? From your post that seems to be the case but that is highly unlikely - population expansion in colonies mainly came from new settlers being shipped over and not from births on site.
 
I suggest you take a look at passenger lists of ships bound for the New World. For example, the passenger list of the Mayflower shows a large number of children were on board. Many died within a few years, but they were on board, and a proportion survived to a ripe old age.

There's a couple of issues here (and probably my fault for not starting the thread with a better explanation).

Firstly, I'm talking about low-medieval colonisation as I said in post #5. I take the blame for any confusion here as I should have made that clearer in post #1. However, be that as it may, the ability of 85 year old dependant grandma to make the journey on the Mayflower is a lot more possible than her making it in a Viking longship.

Secondly, it is likely (as you rightly pointed out) that these (grandma & babes in arms) did make up a proportion of the population, however it would be dramatically less than the average of the overall population. Ie, you can't say that 10% of the population of Great Britain are over 75 therefore 10% of colonists will be over 75.

Is your model assuming that there are no further shipments of people to a colony once it is established? From your post that seems to be the case but that is highly unlikely - population expansion in colonies mainly came from new settlers being shipped over and not from births on site.

Yes-ish. I'll take that into account when needed, but I just wanted to get a guide on actual 'home grown' population increase.

Thanks for your comments.
 
Well just to take some things away but wouldn't most epidemic diseases burn out before such a journey was made? Sure they have animals and are suspect to disease but the chance is minuscule, in OTL the dangerous ones are the ones that jump the inter-species barrier to which humans do not have prior resistance to. But the chances are low enough in the Old World with a population of a few hundred million-over a billion (depends on when), the chances of the domesticates of a community of a 1000 is negligible.

If my Diamond Jared is correct, on the matters of disease they would need at least a large population of a few hundred thousand in relative proximity for epidemic diseases to sustain themselves. That's quite a bit down the road and even then it depends on the spacing and contact between settlements.

if there are 1000 people, they'd probably be between the ages of 0-60 (assuming this is during a colonial age, most people older than that wouldn't go colonizing anywhere). so it stands to reason that 3/14s of the population would not be of an age where they can reproduce.

the calculation also doesn't take homosexuality into account, which is about 10% of the human population.

That doesn't matter if the consequences of no kids=no one to take care of you in retirement. Being gay certainly doesn't stop any practical use of kids.

Also it has been shown in research that having homosexual family members increases the likelihood of their nephews and nieces surviving since the homosexual uncle/aunt have a surplus from a lack of kids. In addition there's tentative research showing that female siblings of homosexuals tend to have higher fertility rates as the gene for homosexuality might be linked to increased attraction to men (would explain the gender imbalance in homosexuality).


Don't forget all the women that die in childbirth.

I don't think male age has any real effect. The women would be marrying older men almost as soon as they could produce children and so while the initial stages of reproduction may be delayed by 10 or 20 years the children would still be being produced. Females would not be marrying their own age group... I think this is a modern problem.

Cool fact, most of the historical evidence are based on noble women: But a recent work done by Chojnacka, Monica PHD from the university of Maryland using inquisition trial testimonies from 16th century Venice showed that the average woman married within a few years of her age. The main reason being is that unlike the nobility there wasn't a vast inheritance to consider nor all the trouble with prestige and bloodlines. Now this may be the exception in Northern Italy but it is something to consider.

Also what's the social structure of the place? Chances are good that everyone would've shared dwellings, that there was a strong sense of community out of necessity and group dynamics. In that case the ability of the male to provide wouldn't fall solely on him but rather the community/extended family. That would also skew the average age of marriage lower.
 
I'm not 100% sure on what you're saying here. Just to confirm, you're suggesting that a colony of 1000 souls will be as follows for 10 years:

1000
1010
1020
1030
1041
1051
1062
1072
1083 etc?

If so that's pretty slow. I'm not saying you're wrong, but it goes against my intuition. If so (and unless my calcs are wrong) after 380 years you're only at a population of 45,000. Again, my calcs could be wrong, or I could be misunderstanding your suggestion - or I could be getting you right and you could be 100% right.

You are right. After 380 years 1000 souls will be 43,865.

It is just Historical trend. You can increase the growth rate (for example to 1.3% - after 380 years 135,391).
Population pf England during industrialization period from 1850 to 1900 grew 1.36% annually.
 
the calculation also doesn't take homosexuality into account, which is about 10% of the human population.
Homosexuality didn't exist as a sexual orientation back then. They were expected to settle down and have kids just like anyone else.

Don't forget all the women that die in childbirth.
Quite so. The high childbirth mortality plus high number of births equals a significant part of the female population dying.
 
Homosexuality didn't exist as a sexual orientation back then. They were expected to settle down and have kids just like anyone else.

I think you'll find that homosexuality existed every bit as much as it did in the 1950's. It was behind closed doors, but it was certainly there. They would be in the population of people who 'just don't get married for one reason or another' Old Aunt Maud who never got married etc. but as I said earlier, they are in the calculation of 'have less kids than others'. 'Zero' is 'less'.
 
Another factor to take into consideration are societal marriage patterns. Contrary to popular belief, during the Medieval and Early Modern Period, surviving records indicate that the majority of people married in their late twenties or even early thirties, given that men needed to establish themselves as able to provide for a family and women often had to work in order to save up for a suitable dowry.

Eh, yes and no. You're right in that historians are now finding that many people married later on in life than otherwise thought, and that it was common to see couples with more than 10 years age different including where the husband was younger. However, these figures are skewed slightly by the frequency with which people remarried in that era. If someone was married at 20, and then by the age of 30 their spouse had died, they remarried. It was considered bad practise not remarry if you were under the age of ~35, and oftentimes older. Women sometimes remarried to very young men all the way into their late 40s simply to have a source of income to support them, and the men often accepted the trade-off as having an older wife could make for a better home even at the cost of not having children - chances are the young husband would see his wife die soon enough for him to get a second crack at children anyway, and people were realistic about early deaths in that era to pointedly recognise that. So if the statistics show that men often married in their late 20s and early 30s, it's only being skewed because the average man probably married about 1.5 to 2x in their lifetime, and the average of those ages trends to the late 20s. It was still common for men to marry when they were just out of their teens, and women did usually marry an older man.
 
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