US 30 year mortgage, fixed rate as they are, are risk subsidised by Fannie Mae and Freddie Mac. It's a regulatory subsidy of the mortgage and ex-mortgage home owning class.

That 'problem' is caused by regulation, structural regulation, not day-to-day regulatory enforcement or change. So where does that risk 'go'? Where do you suggest? What can regulators do to un-risk the risk that's been un-risked/passed on from those that take out mortgages?