AKA 'jingle mail'

aka Strategic default. There was a lot of that in states where the lender doesn't have recourse beyond reclaiming the house.

> On a rental property, he was underwater on the mortgage at the time of the 2008 crash

What I don't understand is why people worried so much about being underwater. As long as you kept making payments, couldn't you ride it out and still own the house as the market recovers?

> Trashed his credit rating but he never had any need for it, he had enough to buy his own house and car outright.

This feels like it should be considered some kind of fraud.

You mean the fraud is the "credit rating", right? It surely wasn't accurate in this case.

The rest of the story in this case was that the tenant had also stopped paying, so it was easier to just let the bank deal with the eviction. As for why worry about being underwater - it's because you don't know the time frame of the recovery; the appreciation might have lagged behind the mortgage interest for the life of the loan, as far as anyone could see in the depth of the crash in 2008.