When Bob Crandall was president/CEO at AMR/AA, he commissioned a study by the University of Minnesota (IIRC!) looking at this issue. His goal was cost reduction in overnight expenses (hotels and crew per diem).

The study concluded that the way to achieve what he was looking for was a large number of smaller crew bases at out-stations so that crews would go out and return the same day or, at worst, have periodic overnights resulting in two-day trips at worst.

I never did hear how hub-basing would be affected. Anyway, he decided the proposed solution was too expensive to implement.