Herewith a response to the following comment by David Parmenter:
"Rawls left open the possibility that some jobs might require higher pay to attract people, but that isn’t his default position. That’s equality. There are, though, many situations in which a higher income would be necessary. For one, my guess is that—if all compensation were equal--most readers of this blog would prefer to be philosophy professors rather than university presidents. (I know I would, although I wouldn’t be qualified to be either). Who would want to give up the classroom and the students for the trustees, the alumni, the donors, the administrative duties and all the rest that goes with being the president?
The example of the guy on the loading dock and the exec reminds me of something Galbraith wrote somewhere, to the effect that the less desirable job should pay more, not less. Both the executive and the guy on the dock presumably would prefer to be the executive and therefore an incentive should be added to attract people from the executive suite to the loading dock."
Galbraith has it exactly right [as usual], but I think your university example misses a crucial point. For Rawls, if you take his argument seriously, as I do, the question is not what you have to offer someone to get him or her to take a job he or she does not want. The question is how to fill key positions with people whose performance would generate enough extra output to produce what I called an "inequality surplus," to be given to the least advantaged representative individual.
There are exceptions, of course, but most of the university administrators I have known have been essentially failed academics -- people who got a Ph. D., produced one forgettable book, and then shifted into administration, ending up running universities where they could never get a tenured job on their academic merits. They are always given courtesy appointments in a department, but no one imagines that in a fair open search they would come out on top for those professorships.
Furthermore, it has been very difficult for me to see that having those people in the positions of administrative authority, rather than someone chosen by random lottery, resulted in something that in the academic context could be considered the equivalent of an "inequality surplus."
I imagine the recruitment speech by the chair of the search committee as being something like this: "We all understand that you aren't good enough to get a professorship in our university on your merits, but if you like being at a university, you can stay here so long as you do a creditable job as president. Take it or leave it. There will, of course, be no extra pay."