Why not treat tenure as wealth, and tax it accordingly? Take a college professor. (Please.) Calculate how much they'll make until retirement from their permanent job. Declare it wealth. Hoover up a chunk. Write in a provision that says they'll get 47% of the amount paid (with no interest, over ten years) if they ever quit, with the remainder going to a fund to pay for college tuitions for the poor. Sit back; make popcorn; enjoy the reactions.
Heh. I like it.