If you can build a freighter then you've already researched the 'Trade' technology. I guess it's just an effect of the campaign (though I've never played it, so I can't say for sure.)

Planet quality/income doesn't matter? I thought they did.... well they did in GalCiv I. Haha I guess that's a stupid reason. Still, seems like they should.

Well, this is how I tested it:

Started a battle of the gods scenario on a gigantic map. Colonized Mars and Earth. Sent two freighters out from each to the major and minor starting planets of one of the other races (I forget which). This gave me trade routes of almost identical distance, removing that factor from the equation. Then I used troop transports to adjust the populations on my planets. This enabled me to test the home planet influence very easily. I also waited until the AI established trade routes with me. This enabled me to test the destination planet influence further.

Result 1) Adjusting your tax rate has no effect on trade income. This rules out income as a factor.

Result 2) Building soil enhancement, terraforming etc has no effect on trade income. This suggests PQ is not a factor.

Result 3) Equalizing the populations on Earth and Mars equalized the income on trade routes going to the same planet from either. Reducing the population on a planet which was a destination of an AI trade route reduced the income from that trade route. This shows that it's the combined population that's important.

Result 4) Starting a game with a massive PQ bonus so that Earth was PQ 40 then establishing a trade route of the same length as above showed no change in trade income. This is further evidence that PQ has no effect.

One other thing...distance is by far the most important factor.

so do econ starbaces "earn" money themselves or add to the money from the trade route and do your econ starbaces earn money from other civ trade routes or only your own?

They do not earn money themselves. They add to the money from your traderoutes only.

stupid question sorry... but... I cant even establish a trade route. I build a freighter, send it to another homeworld, but it will stop outside

Trading is restricted in campaign mode.

I actually don't think that population is the cause of the change. Moving population changes your PLANETARY income for that specific planet. I believe that THIS is what causes the change. I'll have to try adding Stock Markets, etc. without changing population (ie changing planet income without changing planet population- this should bring out the cause.)

I actually don't think that population is the cause of the change. Moving population changes your PLANETARY income for that specific planet.

So does changing your tax rate. That's why I did that test!

Anyway, financial buildings have no effect either (I just tried to be absolutely sure)

Believe me, income has nothing to do with it. Probably the reason many people think it does is that it's the planets with the largest populations that normally have the largest incomes.

stupid question sorry... but... I cant even establish a trade route. I build a freighter, send it to another homeworld, but it will stop outside, nothing is happening. And if I am looking at the menues I can see that trade isn´t researched yet. But I have researched anything which might result in trade. I am totally confused - which technology must be learned for trade, so far I can´t even build a trade module for my freighters. Or is this an effect of the campaign? Is it not possible to build trade routes at the beginning of the missions? No... that sounds strange... I guess I am just blind and stupid... any advice?

The Trade Module is what MAKES a freighter. I'm guessing what you think of as a freighter is simply a cargo hull with some engines? In this game, trade modules become available with the TRADE technology which once researched, immediately give access to the core freighter design. Like most other core designs, upgrade it with your best engine and whatever else you deem appropriate (life support) and send it out. Once it reaches the destination planet you'll get a pop up saying how much the route is worth at that moment and a little minifreighter will show up at your home planet and head towards the destination planet, one square per turn, and then return.

What about the hyperspace speed of the freighter? Those things can be upgraded to go faster? Does this help or no??

So does changing your tax rate. That's why I did that test!

True, I forgot about that. Hehe

What about the hyperspace speed of the freighter? Those things can be upgraded to go faster? Does this help or no??

Not in the way you mean, no. But the further you send your freighters, the better, and obviously the faster they are the quicker you can establish any particular trade route.

The cost of engines is so minimal you may as well make your freighters as fast as your tech allows, after putting on plenty of life support.

i have to agree with that, so long as you don't arm them. if you arm them you have to pay maintance so suddenly the cost building the ship actully matters in the long run.

of course with the growth of the traderoute value even this becomes trivial eventually i suppose....

I have noticed that it is the relative PQ's that determine how much the route brings in, much more than the distance as the manual states. A close PQ26 planet will bring in much more that a far distant PQ18.

Wrong. It's the POPULATION, not the PQ rating. Planet income does NOT matter.

ONLY 2 things matter in trade routes:

1 - population of both planets

2 - distance between the two planets

If the routes travel through the influence sphere of an ECONOMY base, the value is increased ONLY WHILE THE FREIGHTER IS IN THE SPHERE. Of course, if you don't have the proper modules installed of the eco-bases, they do nothing to increase freighter income.

Ah thanks Skyjack.

The Economy base influence was the piece missing in my understanding.
Yey now you've said it, it makes perfect sence. It is how all the starbases work.

Hence starbases on long routes are needed along the whole length to work properly.