I have been curious about why AM stations exhibit the demographic effect you see (in terms of programming, station ownership, etc).

Is it because of something to do with the licensing of the spectrum, and the cost of buying that? Or because of the restrictions around broadcasting (content and distance) of any given station? Or the cost of equipment to operate?

So interesting that something about how the domain operates that creates a different dynamic of what you hear on the radio in AM vs. FM.