I’m here at the advice of Outer Sparta
Anyways, I’ve noticed that this government type wasn’t in the game, despite being decently common as far as government types go
Definition: The Merriam-Webster dictionary defines an oligarchy as “a government in which a small group exercises control especially for corrupt and selfish purposes”. Typically, irl oligarchies are controlled by a group of the ultra-rich who rule over the nation (like ancient Sparta). Trotterdam had an explanation that I rather like, “Oligarchy doesn't necessarily have to be focussed on businesses, even if that's the most common form today and in popular imagination. It refers to any form of society where there is an elite upper crust that can rule the lower classes with impunity (whether that upper crust is large business owners, hereditary nobles, high scorers on meritocratic tests, clan elders, or whatever), but within that upper crust everyone is roughly equal rather than there being a single dictator who can overrule everyone else. Think democracy, but where only 1% of the population are allowed to vote”. Essentially, oligarchies are a council/small group of people according to a certain achievement, lineage, etc. which rule over a nation typically in a dictatorial way.
Possible Stat Changes:
Corruption: Oligarchies tend to be rather corrupt, especially since they are typically made up of the ultra wealth and/or the nobility
Political Freedoms: As stated earlier, an oligarchy is essentially a group dictatorship, so political freedoms (and maybe civil rights) would fall
Wealth Gaps: Oligarchies are very class-based. So, it makes sense for them to greatly increase wealth gaps
Economic Freedom: Maybe this could have less of a decrease, as oligarchies are not always economic