Originally Posted by
debux
XC gives severe economic penalties to regional government buildings, that go descending in value the further you develop your local administration and you secure it, while giving you big public order bonuses to make up for it. It tries to simulate the progressive assimilation of a region as a process embodied in a building, so you have to pay extra (expressed in deductions of regional income) in order to maintain the extensive garrisoning (which is imaginary, expressed in law and entertainment bonuses) which helps you keep the recently conquered region under control. The longer you are able to hold and secure your administration, less is deducted from the regional income, but at the same time, you get less public order bonuses.
In the starting phase it's really extreme (I think it was like a 50% deduction from tax and trade income, alongside with a deduction to region growth, but for 100-80 bonus points of law and entertainment), but you can either choose to set the region as an allied tributary (a moderate reduction of 20% to trade and taxes, but takes a lot less time to establish, plus +40 bonus in public order) or to integrate the region into your own administration, which takes like 14 turns to complete (with three different phases, during which the penalties and the bonuses are progressively reduced and eliminated). This way, it's really hard for recently conquered regions to actually be economically efficient, unless you are willing to go the "easy" way, but having to loose part of the income the region generates, alongside not being able to build and train some of the factional buildings and troops. They also use the "culture"(/religion) feature from BI, which makes region assimilation even harder (although the religion feature in BI itself was already kind of wonky, sometimes I really have to make an effort in role-playing to give a reasonable explanation to some of the events that happen).