In Ymir, population is divided in social classes aggregating individuals with a similar economic activity.
Every Active belongs to a social class. By default, every new Active starts as belonging to the Jobless class and is converted to a different class when becoming employed, defined by the building's type: a jobless Porco finding work into a Farm will be converted to the Farmers social class.
For the simulation's convenience, the stats of individual Porcos in a social class are the average of all the members of their social class in the same territory: the income of a Farmer is therefore the average income of all the Farmers in that territory.