Population

Nations are composed of regions that each have Population (sometimes referred to as "pop") measured in millions. The total population of a nation is one of its most important stats, as pop has significant effects on nearly all other stats, including but not limited to:

• IP.
• Research output.
• The maximum amount of Mission Control Cap that can be built in each region.
• The maximum amount of Armies that the nation can build.
• Cohesion.
• Influence income from public support.
• Pollution output and pollution removal from the Environment Priority.

As a result, nations with larger populations tend to have far greater long-term potential. On the other hand, nations with larger populations are also slower to change their nation stats, because of the need to apply these changes to a larger number of people.

Population Scaling for Nation Stat Changes

The following nation stats are considered to apply to the entire population of the nation:

• Government
• Unrest
• Cohesion
• Inequality
• GDPPC
• Education
• Sustainability

As a result, most changes to these stats are slowed down in nations with larger pop. Specifically, the amount of change is divided by (pop / 50 million) ^ 0.35. This means that changes will happen at the "standard" rate in a nation of 50 million, faster in a smaller nation, and slower in a larger nation. Some examples from the 2026 scenario are:

• India (1476.63 M ): 30.6% change speed
• United States (349.04 M ): 50.6% change speed
• France (69.64 M ): 89.1% change speed
• Singapore (5.91 M ): 211.1% change speed
• Seychelles (0.13 M ): 803.1% change speed

Consequently, two nations with different population but otherwise identical stats would usually develop themselves at the same rate.

Population Growth

Population is one of the hardest nation stats to change - aside from killing people in warfare, population grows (or shrinks) at a slow rate over time, and the player only has limited and indirect control over this process.

As of Version RC6, the game calculates the annual Population growth of a region as follows:

// PavonisInteractive.TerraInvicta.TIRegionState
public double annualPopulationGrowth
{
	get
	{
		double num = 4.49788037409348;
		return Mathd.Max(Mathd.Clamp(num + Mathd.Max(-num, -0.418190741 * (double)this.nation.education) + -0.0624798523403752 * (double)this.nation.cohesion + 9.80843732089162E-06 * (double)Mathf.Min(180000f, this.nation.perCapitaGDP) + -0.115739931206548 * (double)Mathf.Sqrt(Mathf.Abs(this.latitude)) + (double)(this.annualPopGrowthModifier * Mathf.Max(0f, (25f - TITimeState.CampaignDuration_years_Exact()) / 25f)) + (double)this.nation.template.popGrowthModifier - (double)(this.xenoforming.xenoformingLevel / 200f) - (double)(this.nuclearDetonations * 4), -10.0, 10.0) - (double)(Math.Max(0f, Mathf.Abs(GameStateManager.GlobalValues().temperatureAnomaly_C) - 8f) * ((this.template.environment == EnvironmentType.Beneficiary) ? 0.5f : ((this.template.environment == EnvironmentType.Vulnerable) ? 2f : 1f))), -100.0) * 0.01;
	}
}

WHAT THAT MEANS:

• Lower Education increases pop growth by roughly 0.42% for each point of education below roughly 11, up to a maximum of roughly 4.08%.
• Higher Cohesion decreases pop growth by roughly 0.06% for each point of cohesion, up to a maximum of roughly 0.62%.
• Higher GDPPC increases pop growth by roughly 0.098% for every 10k GDP per capita, up to a maximum of roughly 1.77%.
• Distance from the equator decreases pop growth by 0.115739931206548% multiplied by the square root of the absolute latitude of the region. (For specific values, see Region List.)
• Every nation and region has a pop growth modifier, which is defined in plain text in TINationTemplate.json and TIRegionTemplate.json in the game files. These values are added directly to the annual pop growth.
  • Region pop growth modifiers slowly fades away over time, becoming 4% weaker each year until they are completely removed after 25 years.
• Xenoflora decreases pop growth by -1% per 200 levels of xenoflora growth.
  • For reference, whenever xenoflora growth exceeds 100 levels, 50 levels are spent to spawn a megafauna, so this will rarely exceed an impact of -0.5% growth rate.
• Nuclear fallout decreases pop growth by 4% per layer of nuclear fallout. These can be removed through massive investments into the Environment Priority.

The above effects are summed up and then capped between -10% and +10% annual pop growth.

Then the effects of severe Climate Change are applied:

• For every degree of temperature anomaly above or below 8 degrees, population growth decreases by 1%.
• This effect is doubled for ecologically vulnerable regions.
• This effect is halved for ecologically protected regions.

At the start of every month, the population of every region is changed to match its projected annual pop growth rate. But a small amount of randomization between -0.0412% and +0.0412% is also added to this monthly pop change.

If the region population decreases, the nation's Education does too. If you lose more than 0.5 million population in a single month (no, it does not scale with total pop), you get the maximum reduction of -0.005 Education. This can add up quickly in a large nation with many regions, each reducing the Education by a maximum of -0.005 every month.

Note: This Education decrease is only applied by the automatic monthly pop change. Loss of pop from other sources such as war or natural disasters has no effect on Education.