Explain what are wage/salary differentials? How does one determine cost of living? Why are these things important?

Salary/Wage Differentials

Scenario:

A professor is employed by University but has been working remotely since March 2020. His primary residence is in Tampa, Florida which has a much lower cost of living. For example, Florida does not have a state income tax, nor Tampa local wage tax. Pennsylvania and Philadelphia do, respectively. Also, the professor saves on the costs of commuting and dry cleaning. Is it appropriate that the professor continues to earn the same salary he would be making had he been living in Philadelphia and coming to work.

Explain what are wage/salary differentials? How does one determine cost of living? Why are these things important?

Who would be for this? Why? What would their reasons be?

Who would be against this? Why? What would their reasons be?

Are there any other stakeholders to this issue? How do they factor in?

Your recommendation and reasonings?