Faculty put in so much more than just the time they spend in the classroom. A professor can easily spend 2 hours prepping for each hour of delivery in the classroom. They will also spend an average of 2 hours per week following up with students and grading for each hour of class they have taught. Although they may have been paid $80 per hour of “delivery” time, this money gets spread across 5 hours in total resulting in earning $16/hr. This is a fraction of what their full-time colleagues make per hour. The full-time professor gets Prep and Grading time. Part-timers have to "make it work."  Equal Work deserves equal pay.