They are. From all the data I can see, property values for almost all areas in the Northeast and Rust Belt in general are declining (in real terms), except for certain few rich areas in and around the big cities that the richer populace is “escaping to”. I’m writing from mobile, but compare the Fed’s analysis for home prices by state.
Even Buffett says he’s looking at state finances when deciding investment options, and if he’s saying it, surely other organizations are too. It will be a gradual accelerating decline though (barring effects of natural disasters), since people don’t just up and move.