Maximizing Income via Trade with Major/Minor Regimes

[Bellrock]

I’m looking for ways to maximize the income for my empire, and trying to better understand how to do so via trade mechanics. I see in the Trade Report various resources (food, water, metal, etc.) are crossing my borders. Presumable, if I need such resources I can purchase them, or otherwise sell resources thru Traders to generate credits. However, selling resources does not seem to be a major source of credits, in the mid to late game.

It would seem intuitive that there is a benefit to set up Trade agreements with majors regimes, however I don’t seem to generate credits doing so. The Trade Report shows resources being exchanged with majors regardless if I have trade agreements, and I can further do so even if I’m at war with them. To generate credits here, it would seem I need to impose Tariffs, and with majors I can only do so if I have a Trade agreement with them. But to get a Trade agreement, I need a certain relation score, in which said relations drops with a Tariff imposed on them. Furthermore, said major regimes like to drop trade agreements randomly, thus nullifying the work in setting them up.

Which brings up the question of why would you impose a Tariff on a friendly regime, as tariffs are meant to punish factions you don’t like? And similarly, why can’t you impose tariffs on a major regime you are at war with, which the game does not allow? What is the benefit of establishing a Trade agreement with a major, and what is intended purpose of a tariff?

I seem to have lost the thread of what are the benefits of trading with external regimes, and how to benefit in doing so. Early game, you can get access to resources in which you don’t have. But mid/late game trade does not appear to be an income source. How does one optimize their income via trade in the game?

Thank you for replying,
Bell

[Thrake]

It's a complex topic as it depends on what you do as much as what others do. I only play mutliplayer so I'm not sure how the AI will impact trading. As I'm concerned I rely largely on trade to fund high wages with low taxes.

I can fill in some blanks.

The only real limit to how much money you can sell to traders... Is how much credits they have. They will buy up to 1/3 of their credits reserve at the start of the turn worth of one good. Therefore to get all their credits you must be able to sell 3 resources.

To earn credits, traders must either gain it from other traders or from your populace... Through credits you injected into the economy. If you want to use trade to make money, this is not the right path obviously. So you want your traders to get the credits of other traders. One of the commerce feat will help with this. It will also give you better prices when selling to your traders.

For your traders to make money selling goods to other traders, your traders' goods must be cheaper than other traders'. Either you or your private economy (private mines) must be providing these resources in sufficient quantity to keep low prices. In my case, being ahead of competition, ie. selling fuel early game on lifeless planets, or being the first to sell machines or hi tech allows to make some good money. In the long run however this kind of advantage will be lost.

As for trade between nations at war this is suposed to represent smuggling IIRC.