I'm always interested in ways to increase income. Specifically, I have to push every BC I can get from my 1-2 colonies on a particular kind of scenario that I like to play. It's called "Tiny Map, 9 Hard opponents, Alliance Victory enabled, No extra planets". Winning generally requires maximizing your colony potential. But, I reach a point where money is an issue (with like 500+ research on the main planet). I found the following to generate more money:

* Economics Bonus
* Federalist
* Some techs
* Trade
* Trade increase from economy starbase
* Economy bonus (mining starbase)
* External events (unreliable)
* Stock Exchange
* Economic Capital
* Government change
* Raise taxes
* Increase population

There is an upper limit to taxes, and population also starts to take its toll on morale. I can only build so many stock exchanges before I lose productivity. Therefore, what things can I do that don't require tiles but increase economy?

Incidentally, I have never seen a research bonus from changing governments, only increased income.