I haven't commented on "repayment behaviour" because your other comments don't actually mention that. Maybe there's something behind one of the links you posted that explains what you mean by it. I did have a quick look at the not-paywalled ones and didn't see anything of the kind.
(The above isn't a claim that actually the US economy is in a very real sense tanking, or that not-very-rich Americans are heading for destitution, or anything else so concrete. Just pointing out why the things you've been posting don't seem like they address the objection being made.)