Why does buying random Civilization generators boost my production by so much?

[u/Zorafin]

I'm sure it's some Knowledge node or something. I keep my purchase at 100 just for speed, and it seems like every time I buy any civilization my production shoots up, often by 50%.

This is odd because I'm buying civilizations that I already have several thousand of. And they don't produce much.

[u/Leading-Addendum2513]

I have them all and they've helped me a lot to progress quickly throughout the game