Well, I'm not yet convinced on this (yet).
Here's the details of my current game:
I'm the HRE
Large map
Epic speed
It's 1956
I've founded Creative Corporations
It's in 7 of my 19 cities
(These were selected based on where I thought I needed the
and
most)
Here's my finances in terms of costs:
Unit costs 99
Unit supply 3
City Maintenance 92
Civics 101
Inflation 175% x 295 = 512
Of the 92 city maintenance:
Distance to capital 27
No. of cities 36
Colony 1
Corporations 28
I have courthouses in ALL my corporation cities (-75% for HRE) and I'm running Free Market.
I'm able to running 50 %
and the
and
benefits of the corporation, are to me, far outweighing the overall maintenance cost of the corporation.
Granted I probably don't need to, and indeed shouldn't, expand the corporation too much, but isn't that to be expected? The benefits are specific and as I see it, the corporation should only be placed in the most appropriate cities; not every city, and certainly not any city without a courthouse. I also founded the corporation in my most profitable city, one with the specific religion building and all basic economic improvements (alas no Wall Street unfortunately).
So, what's the deal? Seems ok to me for the moment - a fine balance which can easily be lost unless you're extremely careful. As to how the AI deals with the fine balance, God only knows.