Have the game master country and CEO make the undiserable companies. Ones that are causing problems. Like say Airports, planes, Airforce Maintain, upgrade cos, and school companies.
Part of the challenge is the keep undesirable corps sustainable (one's not turning much profit if at all), in order to sustain corps that do generate more revenue. It's a long term investment and realistic when considering how the world economy works.
It's like selling computer hardware; the actual computer is not going to have much profit margin, however the peripherals have a much higher markup. But who's going to buy a mouse or a keyboard without a computer?