>>>>* Lower level managers are often created from senior or valuable employees because a title change is the only way of rewarding them and using their experience
This is the part I’ll never understand. In order to give a larger (than managers) salary you will have to change the title.
Why?
I would throw in also real estate market that makes them cash in on their homes in the city to move to the rural areas (or back home). I think the are way more factors that just this.