I think the standard way of salary negotiations (labour supply and demand) is the only way to define fair salary. If this salary is not sufficient to make decent living, and if we want to correct for that, then it should be corrected by other means, such as UBI, out of compassion or other reasons, but not for fairness reasons.
Based on your own thinking, what would you understand as the attributes of a relationship or agreement that may be considered fair?
I think the standard way of salary negotiations (labour supply and demand) is the only way to define fair salary. If this salary is not sufficient to make decent living, and if we want to correct for that, then it should be corrected by other means, such as UBI, out of compassion or other reasons, but not for fairness reasons.