Tax income, and an effort to make an estimation of tax income vs. number of provinces

Tax income in STW2 works this way:

Tax Income = Effective Tax Rate x Total Wealth of a Province, where

Effetive Tax Rate = (Base Tax Rate + Arts Bonus Tax Rate + Building Bonus Tax Rate + Agent/Character Bonus Tax Rate) x Admin Cost

Total Wealth of a Province = Farming + Commerce + Mining + Town

Note: Administration Cost is explained in this thread.

Wow, that's a lot of terms! But it is actually quite simple. The game clearly shows both the Effective Tax Rate and Total Wealth of a Province. Let's take a look at the picture below:

https://forums.totalwar.org/vb/attac...8&d=1330202565

Here, total Wealth of the province is 2635, while the effective tax rate is 37%. Therefore, the actual tax income is 2635 x 37% = 974. Simple and clear summary.

So we don't really have to crunch the numbers. Although it might seem mysterious how the game got those numbers in the first place.

Here are a few common misconceptions of tax income for new players:

(1) I built a Market, which generates 200 commerce per season. So I earn 200 koku every season.

Not true. The 200 commerce is part of the total wealth of a province. It is then multipled by effective tax rate to be your real income.

(2) My province generates 3000 koku per turn! It says on the campaign map.

Not true. That 3000 koku is the total wealth of your province. You have to tax a portion of it to really make it yours.

(3) I set my tax rate at 30%, so I get 30% x Total Weatlh.

Not true. Good news: There could be other bonuses that adds to the base tax rate of 30%! Bad news: They are all subject to a serious slash by the administration cost.

(4) I have a good 11-star Town Management Metsuke that gives 55% bonus tax rate! I am rich!

A little richer than before. That 55% bonus tax rate is also subject to admin cost. When your empire grows very large, you may only get 20% from that 55%. That sucks, I know.

(5) Tax income sucks! Trade income is the way!

YES, yes, then no. Tax income can't really compare to trade income from foreign trade nodes in early game. However, as the game progresses, we will add more farming (4 levels in total), commerce (mainly from market series buildings), mining (gold mine is the best), and town to the total wealth of the province. It is safe to say that Tax Income will eventually surpass Trade Income as your primary source of income. This is especially true after Realm Divide, where you will have less trade partners and most of your foreign goods are sold domestically for half price.

(6) I have a Sawmill (Iron Mine, Crafts, etc.)... how does that contribute to my tax income?

Depends. Some resources increases commerce level in the province. So that's their contribution. But their primary function is to provide goods for trading. The Sawmill gives you certain units of lumbers, which can be sold to other clans for full price or to your own people at half price. You can check the price of those luxurious goods in the trading tab.

Estimation of Tax Income

Not a simple task, and I have to wonder whether the theoretical result will carry a huge +/- 50% with it...
So instead I will simply record my tax income of a domination campaign and plot it. :sweatdrop: But it will take a while to complete. Will come back later to update this section.

Hmm, I never paid much attention to administration costs. I'm actually impressed CA found a subtle method of tuning the game-play.

Thanks again for a simple/understandable example of how it all fits together :)

Finally I finished a campaign!

Here is the promised chart of the relationship between Tax, Trade, and number of provinces.
A very irregular relationship...
But it is safe to say that after the March patch, it becomes much more difficult to establish trades, and therefore Tax income has become the main source of income.

https://forums.totalwar.org/vb/attac...7&d=1336322387

https://forums.totalwar.org/vb/attac...8&d=1336322389

This chart shows the Tax and Trade income vs. number of turns. Also included in the chart are army and navy upkeep.

https://forums.totalwar.org/vb/attac...9&d=1336322389

This shows the missing link - the reationship between number of provinces and turns.
There was quite a long period of wait before triggering Realm Divide. Then there was nothing to worry about after RD.