Different people are going to have different conclusions regarding what it is they do and do not deserve, so it's kind of impossible to have a doctrine that across the board defines it. Everybody through a mix of desire and interpretation thinks what they should give and what they should get for it is different, some will think a doctrine is giving them more than they deserve, many more will think it isn't nearly enough.
Although fairness is a term used to describe a decision reached through equal consideration of all aspects of a situation, it is a somewhat one sided term in that one side is always going to see a situation as more or less fair. This is simply because though people often use the same arguments in presenting a case for fairness, they assign different priorities to those arguments. Unless everyone always assigns the same level of priority to argument points on the way to determining fairness, then it's impossible for fairness to ever really exist.