The income demands are driven by the COST OF HOUSING-—and OTHER COSTS OF LIVING
I remember in the 50’s that Madison COL was 2nd ONLY to WASHINGTON DC.
It is not a surprise that the county housing a major university system is one of the highest housing markets in the country or state.
Here in NH some of the most expensive markets are where UNH and Darmouth are located. Universities provide many six figure jobs. Some are high six figures. FYI, the highest paid person working for the state of NH is the UNH hockey coach.
In addition, there are lots of housing around colleges where six or more students live in a house. These are great rental houses for the house owner. You have guaranteed renters every year whose parents pay big money for their kid to live in a dumpy property. I know I lived in a couple in Syracuse.