This civic comes so late in the game that I wonder if it's ever a good idea to use it... If the game goes on that long, I'm either going for a Space Race or possibly late war/domination - in either case I probably want to maximise and it seems like the best way to do this is either through Mining Inc (possibly augmented by a food corp,) or through State Property with a lot of workshops and water mills. If I'm using corporations it seems like Free Market would be a than Environmentalism, though I guess if I only spread the corp to a few cities with the highest then the upkeep costs wouldn't be so bad. Generally though, if I get useful corps early enough then I want to spread them to as many cities as possible as the bonus is proportionally higher in cities that did not have much production to start with. I guess another reason would be to make someone whose favourite civic is Environmentalism (Sitting Bull?) like me more to try to get his vote in the UN election.