I started a new game and was lucky enough to experience an economic boom from beginning to end. I'm fairly sure now that the economic boom has always had a 2x multiplier, and that the reason why my taxes are lower than expected is because the game placed an invisible penalty on my economy as it grew larger. At the beginning of the boom, my income was only 9% lower than expected, whereas at the end, it was 15% lower. Tax incomes from individual planets actually shrank even as overall income grew due to more planets being colonized and developed.

The AI, on the other hand, had its hidden bonus grow from about 20% at the beginning of the boom to over 40% at the end. The whole time I was far ahead economically. In the save game I uploaded, I was only a little ahead of the Torians and well ahead of the Thalans, who had 24% and 44% bonuses to their economies respectively.

I suspect that the game gives out these penalties or bonuses according to how much a civ is earning relative to the rest of the playing field, which may help the poorer ones catch up. Still, in one of my old games, two AIs were earning far more than anyone else while I was in the middle of the pack, and the only "help" I got was a 0% tax penalty...

There are two known penalties to your income, if your treasury is too high. A 50% penalty to your trade income, if your treasury is 10k+, and a ~20% penalty to your tax income, if your treasury is 20k+. What you describe sounds like an additional penalty, and I'm a bit weirded out that nobody noticed it before.

Sounds about right. Can't say that I like it though. GalCiv has always been touted as having an AI that knows how to play the game. And as far as I can tell it that is the case. It shouldn't need such a "help" mechanic. >:(

Also, sorry for the late reply. I was busy IRL and then completely missed your post.

It's all right, you've already been very helpful, and I appreciate any time you can give to answer questions. :)

Have you also noticed the AI's uncanny ability to find habitable planets and resources in the unexplored fog of war? Everyone, especially Stardock, insists that the AI doesn't get such omniscience cheats. I wanted to take some screenshots and ask around, but then I found this thread: https://forums.galciv2.com/361996/computer-ai-and-hidden-map-not-being-hidden-from-ai-debate

People there not only agree that the AI can do such things, they simply accept it as part of the game, even though it goes against Stardock's claims.

In my experience, it seems AI constructors and scouts have an AI-exclusive ability to find resources and habitable planets in the same way the player's survey ships can use the auto-survey ability to find anomalies in unexplored territory. An AI scout always knows exactly where a habitable planet is, and will make a direct beeline for the closest one. Even Terran scouts without Stellar Cartography can do this. Constructors, meanwhile, know exactly where a resource is - I've seen AIs build a constuctor very early in the game and send it in the opposite direction from where its scouts and flagship went, directly into an unexplored resource.

However, I don't think Stardock is 100% lying when they say the AI can't see through the fog of war. A colony ship, I've noticed, will not leave its home planet until a colonizable planet has been scouted through the fog of war. It's as if there are two different AIs: one controls scout ships while the other controls colony ships, and they don't communicate with each other. The colony ship AI can't see through the fog of war and doesn't do any scouting, while the scout ship knows exactly where the habitable planets are and will go to them without fail. As a result, the AI avoids wasting time by never accidentally sending colony ships to systems without habitable planets, but simultaneously wastes a lot of time by never using its colony ships as scouts.

On the whole, this isn't terribly unfair to the player; it's actually the constructors that are unfair. Imagine if player constructors had an auto-build ability just like auto-survey, but instead of anomalies it found resources...

Is it intended that there are no research technologies to research? I researched traditional research (first research technology) but after that there are no more research technologies to research. I`m pretty sure, that there were more research technologies to research in the game, even without the community patch. So, is this intended? And how do I win by research victory, when there are no research technologies to research? I`m confused now, it seems as if I have to uninstall this mod again, to be able to do more research. Or is this a bug?

No, that's definitely a bug.
You should start with traditional research already researched. Are you using a pre-made custom race or an already customised standard race? The game stores the data for those in a file, which doesn't get updated, if you use mods. So that could be the issue. Remaking the custom race or clearing the customisation of the standard race should do the trick. Though in either case it would mean starting a new game.

I hope this helps.

Okay, I will try that. I indeed use a self-made race since I installed GalCiv II. Thanks for the info.

Nope, it`the same. I don`t get any research technologies to research. Damn!

Now I deinstalled the mod and also I deinstalled GalCiv II, reinstalled both and guess what? The same fecking thing!!!
And I realized, that not only research technologies are missing, but industrial technologies too!!!
I give up now!!!

Sounds like registery changes.

Hm, now I read the whole thread here again and it seems as if the mod never really worked. I had always nore than 100 customization points and if the mod is working, i should only have around 10 points. Hm, something is clearly wrong with my game.

Are you sure, you've installed the mod in the correct place? That's the one thing I'm thinking of. Still, even if you didn't or forgot to activate the mod in the game options, you should still have research and industrial techs. The Community Update didn't remove them. Neither does my mod. So them not being there is really strange. Every tech tree has them, even if they are called or placed differently.

Well, after de-installing and re-installing everything a few times it suddenly works, and the research technologies are researchable now.
Well, those are the wonders of the computer age! :-D
But one question: Is it intended that all planets with a quality of 12+ are extreme worlds and only colonizeable after researching those extreme world colonization technologies? Hm, next time I start a new game I should take a closer look at the options, maybe I didn`t choose the right options...

I'm glad to hear that! :-)
You'd need to look at your game settings for that. Extreme worlds isn't something I can directly affect with my mod. The only ecxeption are the techs you need to research in order to use them.

Well, I found now one white world which is not an extreme world, all the others are. But I guess you`re right and it has something to do with the settings.