It's real, it's 20k (sorry to echo you, Purge), and it applies as a racial "bonus"-of 20%, IIRC.
You're getting 10 from Xeno Economics and 5 from Xeno Bank Construction, at a minimum. An economic resource or two grants you either 34 or 39 a piece (my memory's foggy on that one), and if you picked a race that had some inherently or spent racial points on it, you've got that too. Not to mention you can get up to 30% from governments alone. Point being, most games, you're probably looking at at least a 150% -bonus- (that's a 2.5x factor, if you will) to your economy. I'd go so far as to say this is a probable although not certain value even on a tiny map.
So in the above example, you drop from making 2.5x your base income to 2.3x your base income; a total loss of ~8.6% of your "real" income. On larger maps, with more economic resources, the effect is even less noticeable.
So, to reiterate what Moosetek said-by the time you're making that much money it doesn't matter.
@Swicord
My hunch is that is largely due to your increased production/ships (military)/happier population that you can tax more rather than the fact that you had that additional 20% racial bonus (which is the other way of looking at it, really). It's really insignificant...although scores would be higher without it, even with the area under the curve mattering at least as much if not more than the actual values, it would not be a significant increase-especially after taking the logarithmic nature of score into account.
Let's take a gigantic galaxy, for instance. We'll pretend we're playing Thalans as they get an innate 25% economics. 25 innate+30 racial points+20 political party + 15 techs + 30 government + 100 (let's go evil, shall we?) gives us 220% /bonus/. Assume we have 5 or 6 economic resources-a decently safe bet; I've seen some gigantic games with 8 or more, but those are rarer. I'll round up because frankly I'm lazy. 6x39 ~=6x40=240, add to our current 220 and we have a 460% bonus, which gives us a factor of 5.6. (In TA, with tech trading on, this gets even more ridiculous.) Not to mention all those anomalies you probably picked up, right?
If we're above 20,000bc, we're only making 5.4x our base income-which happens to be about 3.7% less than our below 20k bc value.
Which makes it more significant than I thought it was...but still, I don't believe I'm exaggerating too much when I call it insignificant.
