The Madison-Davis Airlift is the tendency for people who live in these two cities to move from one to the other. Many professors and other people in Davis, California got their degrees in Madison, or have lived in Madison. The same is true for the reverse.
The Madison-Davis Airlift can also refer to those people in Davis who wish they were in Madison. Or vice Versa.
It has been suggested that Portland, Oregon may also be part of this loop, and that migrations may follow a Davis-->Madison-->Portland-->Davis route.
Davis to Madison
These folks recently made the move to Madison from Davis.
Madison to Davis
These folks have had enough of the Midwest and have headed West to Davis.