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 in the 2022, 2026, 2070, and 2003 scenarios, or
• (pop / 50 million) ^ 0.30 in the Broken Earth scenario.

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

The difference in the Broken Earth scenario is relatively small in practice - a BE country with the same population as 2026 India would go from 30.6% to 36.2%, and a BE country with the same population as the 2026 Seychelles would go from 803.1% to 596.3%.

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.