David Neibig

Growth, Immigration, Birth and Death Rates

25 posts in this topic

Does anyone know how the daily Growth Rate relates mathematically (if anyone has the actual equation that'd be great) to the immigration, birth and death rates as well as current population?

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I don't think anyone knows the equation. Its likely very complex.

A few things to keep in mind though:

More land, more immigration.

More population, more births.

I imagine that the birth rate, for example, gives you the number of births per hour, or minute, or something.

The growth rate is obviously a daily number.

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I've been experimenting a little and this is what I figured out so far:
The rates (birth rate, death rate and immig. rate) denote the number of people for every 1000 of your current population per day.
So if your population is 850,000 and your immigration rate is 2.5 then the flat number of immigrants moving to your nation is:

2.5 * (850,000 / 1000) = 2125 immigrants per day

The total daily pop. growth shown on your nation page seems to be:

pop. growth = (Birth r. + Immig. r. - Death r.) * (pop. / 1000)

I have no proof of this but of all the possibilities I considered this is the only that gives sensible figures.

 

As Grillick said, the death rate shown on your nation page never changes so I worked back what it should be using the above equation. In my case it's hovers between 12 and 13.

Maybe this is a bug in the UI but I also remember reading a thread that said that, back in alpha, your growth rate depended on dozens of factors. This might be the same in beta.

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Thanks all for your help so far.

I'm aware that various factors affect growth rates land etc, this isn't news to me but thanks anyway for trying to help!

 

BitJunky if your equations are correct and my death rate is about 12.02 rather than 3.00 then I do get to the correct growth rate figures.

 

Would appreciate it though if one of the mods or devs could look into the death rate issue to confirm whether the 3.00 vs 12.02 issue is actually the case.

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Would appreciate it though if one of the mods or devs could look into the death rate issue to confirm whether the 3.00 vs 12.02 issue is actually the case.

 

In case any dev. actually reads this, I would also like to know how life expectancy fits in. The number changes sometimes but it's not clear how, if at all, it affects death rate or even net population growth directly.

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The total daily pop. growth shown on your nation page seems to be:

pop. growth = (Birth r. + Immig. r. - Death r.) * (pop. / 1000)

I have no proof of this but of all the possibilities I considered this is the only that gives sensible figures.

That would be the only way for it to make sense - except it doesn't seem to quite match what my nation stats show... It looks like the rate is more like per 2100ish people. Do we all have the same number though?

 

I'd like to know if death rate can be changed.... Wouldn't better health care lowers it?

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You would also have to take into account for any laws that increase immigration, birth rate, etc. as those would affect your population growth.

 

 

I don't think I've ever seen my death rate change. Does this agree with what everyone else has seen?

 

In Alpha, I remember seeing the death rates of inactive nations being 18.00. I don't know what caused it do that, but I always assumed it was the lack of land due to the constant raiding of said inactive nations.

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In case any dev. actually reads this, I would also like to know how life expectancy fits in. The number changes sometimes but it's not clear how, if at all, it affects death rate or even net population growth directly.

 

I opened a ticket last night to ask about the death rate issue that included a link to this thread, hopefully they'll provide definitive answers.

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You would also have to take into account for any laws that increase immigration, birth rate, etc. as those would affect your population growth.

 

I understand that, but shouldn't those affect the birth rate / immigration rate, which in turn changes the population growth? In other words, if those are factors, those should be reflected in the birth rate stats as well!

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You would also have to take into account for any laws that increase immigration, birth rate, etc. as those would affect your population growth.

 

 

 

In Alpha, I remember seeing the death rates of inactive nations being 18.00. I don't know what caused it do that, but I always assumed it was the lack of land due to the constant raiding of said inactive nations.

 

Also starvation. I'd expect lack of land to create a negative immigration rate.

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Also starvation. I'd expect lack of land to create a negative immigration rate.

 

It does. There are lots of inactive nations right now that are shrinking because of it.

 

 

That would be the only way for it to make sense - except it doesn't seem to quite match what my nation stats show...

 

The numbers don't match because there is something fishy about death rate, hence David's ticket.

 

 

It looks like the rate is more like per 2100ish people. Do we all have the same number though?

 

This number would vary for everyone if the death rate shown on the nation page is indeed wrong. The reason the /1000 is in there is because the rates are effectively a percentage (times 10) and they need to be converted into a ratio between 0 and 1. It doesn't really make sense to choose any number other then 1000 to do this.

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Also starvation. I'd expect lack of land to create a negative immigration rate.

 

True, and inactive nations are probably negatively impacted by a lack of supply of food, energy, and infrastructure resources. Those most likely also have an impact on growth rates.

 

Edit: I just thought of this as I walked away from my computer. In real life, developed nations tend to have lower population growth rates. I don't know if the developers have included that in the game, but it could be a possibility.

Edited by chrisford

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I have a pretty new nation and a high birth rate (32 days old and an 18.14 birth rate.) The net growth rate for my nation is 4,156 people per day.

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True, and inactive nations are probably negatively impacted by a lack of supply of food, energy, and infrastructure resources. Those most likely also have an impact on growth rates.

 

Edit: I just thought of this as I walked away from my computer. In real life, developed nations tend to have lower population growth rates. I don't know if the developers have included that in the game, but it could be a possibility.

I guess that's represented by how literacy rate lowers growth rate?

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I guess that's represented by how literacy rate lowers growth rate?

 

It may not even be in the game, i was merely thinking about any x factors that might have an effect.

 

 

I know that you start getting positive results from feeding your people several types of food, perhaps one of those results would be an increase in the population growth rate.

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It may not even be in the game, i was merely thinking about any x factors that might have an effect.

 

 

I know that you start getting positive results from feeding your people several types of food, perhaps one of those results would be an increase in the population growth rate.

Just curious, how much of a difference does it make? I have only been feeding the same thing to my citizens.

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Per the Logistics page, under food:

 

Distributing food to your population prevents starvation and hunger among your people which will lead to rapidly increasing death rates, and famine. Eventually positive results on your nation will occur from feeding them a balanced diet of multiple food types.

 

That's all I know.

 

However, based on the wording of that section, it sounds like time is factored into the death rate too. Not feeding your people for one day is different, from, say, not feeding your people for two weeks.

Edited by chrisford

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I vaguely remember a thread in which people confirmed that this diet thing hasn't been implemented yet.

All I know is that for the first couple of weeks I fed my people all kinds of food but then I switched to a single food type to see if it matters. It didn't have any effect whatsoever so my people are forced to eat cheese 24/7 ever since.

Way to go for sieving out any genetic predisposition within your population for lactose allergy... ;)

 

I guess that's represented by how literacy rate lowers growth rate?

Uh, does it? I mean, is this an actual in-game mechanic and is it implemented?

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Does anyone know what happens if your population reaches zero?

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I suspect it's impossible, since immigration is negatively correlated with population density.

Edited by Grillick

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I suspect it's impossible, since immigration is negatively correlated with population density.

But if you sell your land it could be possible to keep immigration rates in the negatives

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Probably not. I'd bet real money that the equation normalizes at the population if your cities, even with 0 land (if it's even possible to sell down to zero land - your nation rents space for its cities?)

Edited by Grillick

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Probably not. I'd bet real money that the equation normalizes at the population if your cities, even with 0 land (if it's even possible to sell down to zero land - your nation rents space for its cities?)

You're probably right.

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