I used "realm income" from the stats page. Realm income is calculated, as far as I can tell, from regional production values multiplied by the gold value, possibly then by some percentage, but that shouldn't matter assuming it's consistent.
Tax rates don't matter, because tax rates occur after productivity; they occur after the point of collection for my data. Which is good, because I wanted to find economic output, not distribution. In the long run, sustained taxes at very high levels (enough to cause unrest) or very low levels (too little to fund investments or effective defense and management) I suppose do matter, but that's pretty indirect.
Investments do matter, because investments affect production levels (productivity rising over 100% and whatnot), and thus final gold output.
In terms of the question "does this matter," I see that as equivalent to asking "does the Dwilight University matter." No. And most of the wiki doesn't "matter." It's superfluous player-generated information about a fictional world. Mine is trying to be something other than completely arbitrary (I did not do any balancing at all to overall income, other than to add some zeroes for convenience' sake; I did do some balancing for distribution), and to inform us about how the people in various realms might be living. If we assume a uniform price level (an idiotic assumption in terms of realism, but about right from game mechanics terms, though larger realms would have wage-inflation for soldiers-peasants due to game mechanics), then those numbers give us relative wealth of peasant and aristocrat populations compared to each other.
So that's its use. A bit more RP depth, based on something other than whim.
Perhaps write a wiki economic treatise based on it
