Ideologies

Communism is an ideology mainly focused on developing your teritorry. With the non-core income buff, can be useful for countries with not that much cores.

Democracy is an ideology which most of the nations start with. It has a massive income buff and a good non-core tax bonus. It also has the highest compliance gain, making it very easy to stabilize and increase your nations tax even more, but due to a high war cost is slow to expand.

Upkeep cost and development cost are normal.

Fascism is an ideology which is useful for holding a large military, with its 75% upkeep cost reduction. It has a tiny tax income buff but a very low non-core tax income. This is going to be terrible for small nations without any formables or cores.

Authoritarianism seems like a mix of all other ideologies. It has a decent development cost reduction and a small tax income buff. It has a large political power gain buff, so if you want to switch ideologies that might be useful for you