VERY valid point from Macsen Rufus!

Of course - the "empire" is generating income via taxes...it would be the various merchants within the empire that are actually doing the buying and selling and profit-making....so trade between provinces within the empire would result in taxes raised being offset against credits claimable by merchants....The taxes must be some form of "activity tax" rather than an "income tax"....

Sorry - I just like to be able to take stuff that happens in the game and find a sensible, in-context explanation for "why it should be so"...