Not entirely true that negative is always better. Saturn for example were benefiting 3 rivals teams to the tune of +9 (the balance was -18, but they would have gotten 9 trade domestically anyway) whilst getting no benefit back from this for themselves.
If there is situation where there are two civs trading only with each other, a negative balance on the one hand means you have larger (or more cities) which is obviously good, but on the other hand it means your trade partner is benefiting more from the trade relationship than you are (not factoring other multipliers of course). So it really depends on what you mean by "better".
Our trade balance is negative right now because we don't have a visible, unblocked route to any other civ with which we have OB. Whereas one civ has an unblocked visible link to us.
Speaking of which, should we offer SANCTA OB? If we don't get any trade we'll know the blockage is between us and them. They don't have a route to us but we do to them, so we'll gain and they won't.
If there is situation where there are two civs trading only with each other, a negative balance on the one hand means you have larger (or more cities) which is obviously good, but on the other hand it means your trade partner is benefiting more from the trade relationship than you are (not factoring other multipliers of course). So it really depends on what you mean by "better".
Our trade balance is negative right now because we don't have a visible, unblocked route to any other civ with which we have OB. Whereas one civ has an unblocked visible link to us.
Speaking of which, should we offer SANCTA OB? If we don't get any trade we'll know the blockage is between us and them. They don't have a route to us but we do to them, so we'll gain and they won't.