There is a trope known as Command and Conquer Economy in many strategy games where the various governments of the in-game world seem to be the only factions constructing base facilities. This makes sense in military situations (outside of ones involving private mercenaries and their bases) but makes little to no sense in ones modelling economics other than communist ones.
Accordingly, I have come up with an idea for simulating the private sector in game. There would be an additional “slot” for building facilities (such as temples, hospitals, schools, etc.) in each of the bases/cities/settlements/etc and doing research that would represent the private sector, not being directly controllable by the player.
The player (be he human or computer), in some economies (socialist, fascist, environmentalist and mixed ones) would be able to choose a priority (exploration, research, culture, etc.) for the private sector to focus on in construction and research, while still having his own slot representing government works and research.
In other economies (communist and simple ones), there would be no second slot, and all development would be controlled by the player. While in the free market option, the second slot would not be player controllable, but would work twice as fast and build/research according to demand (i.e. if your society is highly religious, temples and monasteries will be build, if it is highly intellectual, universities, academies and colleges will be build, if it is highly cultural, theatres, studios and art galleries will be built, etc.) while the player’s first slot can only be used for research and construction of military units, representing the restriction of government under laissez faire capitalism. Also, these new facilities would not cost the player anything to run, unlike in other economies, where they carry lesser maintenace costs (representing subsidies and regulatory costs).
The free market system would, as it is in real life, have great benefits, but other economies would have benefits to players who want more control over their civilizations or want to wage massive wars, much as in real life.
A second idea I had is to have multiple options for currency civics, namely:
Barter: Low upkeep with no effect other than limiting city size
Commodity: Medium upkeep, with steady growth and normal city sizes.
Fiat: Creates temporary booms, but with great busts. In general, the best usage for it would be for players who were planning a blitzkrieg assault. For example:
1900: Player switches to Fiat
Next 15 years: Player pumps out lots of units thanks to this quick wealth.
1915: Player switches back to commodity with a recession, but not as severe as that normally caused by 20 years of Fiat.
Carbon: This one’s a little more speculative. It would only be available in the late stages of the game, probably from the same tech unlocking environmentalism as a civic option, and be tied to the amount of pollution produced by cities.
Energy (A tip of the hat to Alpha Centauri): Highly speculative, probably tied to power production in same manner. Would only be available much later in the game, around 2040s or so. Would increase production greatly.
Any thoughts, critiques, questions?