I think they should be transferable, but they should only last for 5 years or some other reasonable fixed term. Make it long enough that there is some stabilit

I think they should be transferable, but they should only last for 5 years or some other reasonable fixed term. Make it long enough that there is some stability; but not so long that it becomes something that is like a real estate or mineral rights investment. Let the city auction the fraction of them that come up for renewal each year; so that instead of a private entity making money off a scarce city resource the city would.